New roof with ice/water shield leaking?
I’m the HO. This is a new house construction one part of which is a 2.8 in 12 sloped roof over an enclosed breezeway which butts up to the brick of the house. I specified ice and water shield on this roof (because of its low slope) before signing the contract with the builder. The print from the architect, which the builder worked from, also specified this.
Long story short, the roof leaked in one area (that I know of so far) from day one. They returned to fix it by putting caulking under the tabs of the shingles directly above the area of the leak. I suspected that the water was coming from a valley located above the leak where a very steep roof met the section of shallow-sloped roof, as there was no dam or valley divider installed to stop the water from rushing down the steep slope and going up under the shallow-sloped shingles. However, even if this was happening the valley flashing should be over top of the ice shield and that should prevent the water from penetrating the sheathing. (I would surmise that there is more than one problem here.) I then suspected that there may not have been any ice shield installed at all. Both the builder and his sub insisted there was.
When a hole saw was used to drill holes in the roof about 6″ to 10″ away from the brick to install piping for a solar water heater … guess what? … no ice shield in the core slug!!! The explanation from the builder is “since ice and water shield acts as a vapour barrier they don’t run is right up to the house wall, but stop short of it a bit, as the manufacturer suggests”. (Note that, technically speaking, for all intents and purposes of a vapour barrier, BOTH sides of the roof are exterior surfaces.) The soffits underneath are well-vented aluminum, so drying can readily take place through the plywood roof sheathing. This explanation makes no sense to me, however, I’m open to learning something new, and I will be asking the builder to clarify this.
I called the big local roofing supplier and none of them had heard of it.
My reason for posting is to find out if anyone has ever heard of such a detail or has ever done such a detail in a house.
Thanks in advance for your responses – Brian.
Replies
It's supposed to be installed at least a foot from inside of the wall. The point of it is to prevent water from leaking through the shingles when it has been backed up by ice dams along the eaves. I always run at least two runs (6' wide) down the valley anyways, but it is still just a backup. Nothing can make up for a well-designed roof
BS.... any flashing should turn up the wall and the brick counter flashing should come down over that..
pics would be helpful.......
Mike Smith Rhode Island : Design / Build / Repair / Restore
If there was a roofing contractor involved , don't bother to call him back because you voided your guarantee when you let someone else penetrate the roof after he left to install the vent for the water heater.
It sounds like your suspicions are correct . The ice shield should have been installed up the sidewall and in the valley. It is difficult to tell though if I can't see the roof and your description is a little vague. Where the brick sidewall meets the breezeway roof you should have special flashing made that kerfs into the brick or step flashing with blackjack behind it. Where the breezeway meets the steep roof there should have been a minor tear off and re roof to properly apply the ice membrane. Ice membrane is not necessary on an unheated surface such as a breezeway and you are wasting money to apply it there.
not necessarily a waste....
a coupla yrs ago I rebuilt a roof that spanned both living and deck space.
They wanted to match the existing arch shingles.....the steepest I could make it was 2.5/12
The shingle man. wanted ice shield on the whole deck.....
the local inspector wanted the whole deck vented if ice shield covered everything.
so I had to cover the entire deck with ice shield first....to make both happy and get the final result the customer wanted.
I was told I could have gone down to a 2/12 and still have the full warrenty..that may have been the thinking on this one.
my roof deck on that one was a big shed...off the rear of the house....one story bump out on a two story brick house.....
In the posters case....I'd be thinking along the lines of Mike's post ....
stick the membrane over the entire surface....run up the side walls.....then step flash.
maybe even flash first....stick the membrane to that ....then counter flash with step flashing....
Sounds like a bad design from the start .....gotta pay special attention to those archy drawn specials.
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
Make that Mike and Jeff and Piffin all agreed that this HO speced the roof correctly with full ice and water shield on the low slope.
Roofer took a short cut and screwed him over. Whoever said something about vioding the warrantee is missing the boat. It was leaking before that hole was drilled and since the roof was not done to specs, the roofer voided his own work and reputation, IMO.
Then to top it off, the builder is lying or bluffing.
I would be demanding that the builder be respoinsible to get the roof done the way it was speced in contract..
Excellence is its own reward!
Looks like the roofer is going to do a minor tear-off (cringe, grit teeth). Could be worse... if I had chosen some other local builders they might have walked away.
Actually, I'm responsible for the design, not the archy, who essentially was my CAD person and advisor. The roof design was not faulty, the detailing of the roof flashing by the roofer was (after all, he IS a roofer isn't he?) My blueprints already had much more detail than most prints do, but somehow I figured that a roofer should have been able to handle this without my input. So I did err in assuming such.
I did give fair warning that the solar panels were going to be installed, even after the first attempt at repair.
I must make a general comment on my surprise at the amount of things that are done over a second (costly) time in new construction when it would have been so easy to have done them right the first time. How much extra work would it have been to place a valley dam at the time of construction, particularly in an area of such obvious risk of trouble? It may not have prevented the leak, but if nothing else it would have eliminated that as a source of the leak. A gamble was taken and lost there. And a second gamble was taken and lost with the misplacement (?) of the ice shield.
I would surmise that the gamble is taken often and won on homes other than my own.
The expression in my field of expertise (design, engineering, manufacturing) is "Quality is free", and is echoed by someone in this forum (apologies for not recalling your name and giving proper credit) who's handle says "Do it right or do it twice". Well said!
Regards, thanks guys, and I will try to take and post a picture, as it is quite difficult to explain in words. - Brian.
"A gamble was taken and lost there. And a second gamble was taken and lost with the misplacement (?) of the ice shield.
I would surmise that the gamble is taken often and won on homes other than my own."
Unfortunately, the gamble is often taken and the sub runs or is unknown by the time the problem is discovered by the new owner - shortly after warantees are off calender.
I have spent a large part of my working life correcting careless work left behind by others. I've always taken the attitude that it is cheaper and easier to do it right the first time but I'm afraid it is not that common..
Excellence is its own reward!
ice guard specs I believe say you can't use it on that little bit of a pitch..no?
a
Its very hard to grow, because it's difficult to let go of the models of ourselves in which we invested in so heavily
http://CLIFFORDRENOVATIONS.COM
Piffin,
the roofer may well have done a cruddy job----BUT
ultimately the blame lies in the horrible design.
come on guys---YOU KNOW putting shingles on this low of a pitch is a BAD idea, regaurdless of how much icegaurd you use.
the design of the slope is faulty---much to low for the primary material specifyied. If the designer insisted on that low of slope ,the designer should have known to specify a material suited for low slope applications. counting on Icegaurd to bail out a poor design---pretty cheesy.
the biggest mistake the roofer made---was in not refusing this poorly designed job in the first place.
BTW---2 items to note
1) icegaurd does not always adhere to the substrate and perform as planned. about 8 years ago I was asked to put new flashing on an old chimney. As part of the project( as a backup) I put icegaurd around the base of the chimney and coved it a few inches up the sides. substrate was clean,dry,north facing, and work was done during warm weather.
2 years ago the customer was ready to totally replace the roof. when we tore of the old roof we found that the icegaurd I had installed 6 years previously had never adhered to the deck----It came off like 30# felt. good thing it was only a back up---not something I was depending on. chimney never leaked a drop however ,because the primary material---in this case the chimney flashing---worked as it was supposed to.
2) recently had cause to look at a problem faced by a homeowner who had G.C'd his own house."DESIGN" included--not one--but two blind valleys draining against the walls of the foyer----wonder why this design has problems?
I'll respectfully disagree.
The low slope was only 2.8/12. Normally the minimum allowed by manufacturers for asphaltic shingles is 3/12. I doubt seriously that you could walk onto a roof with that minimal difference in pitch and know that it is that slight amount off. ( I will walk away from some things like a dead valley tho)
The greater problem is that I&W was speced and the roofer chose to ignore the specs and then lie about his failings when what he should have been doing is to place the I&W even if it were not speced. The key that I would have been noting if I were the roofer is the different pitches which often cause trouble. I would definitely want the extra insurance.
As for how to treat that valey, There are only two ways that work for unequal pitchjes, IMO. One is a lapped valley where the low pitch is laid first and the uppr is lapped over. The other is to use a "W" valey metal with a return break in the edge of the metal. I prefer the latter but the former is acceptable for some designs and lower budget jobs..
Excellence is its own reward!
Piffen,
I have no objection to your dis-agreement. Basically we only disagree on where we each drawour line in the sand.
Personally I won't generally install shingles on less than 4/12. you.it seems ,draw the line at 3/12.
also it depends where the low pitch roof is.
On the house I posted pictures of a few weeks ago---there was a low pitch roof not shown that I shingled---maybe 2 1/2 or 3/12 at the very top of the house.
about a 2 foot area. I icegaurded it and shingled it. I was confident because it will recieve minimal water. the same area at the BOTTOM of a roof--I would NEVER shingle. to much water draining on it. If I am gonna shingle a 2.8/12----I am gonna pick the location. An 80 plus year old ,problem free house is a good bet. A homeowner designed new house---not a good bet.
think a homeowner designing his own project who designs a 2.8 /12 pitch into his roof---will pick a qualified roofer for the project? I think the results tell you the answer.
I bet you he has a lot of water draining on the roof----and the qualified guys KNEW better than to accept a spec of shingles on a 2.8/12.
Rubber,metal,torchdown,sa modified---hell even crappy peel and seal would have been better. this is a maintenance nightmare and the designer got what he had coming.
Good argument!.
Excellence is its own reward!
The W valley is actually what I had in my mind and "valley dam" was the only way I could think of to describe it.
If the implication is that I just went with the low bid, then that would be quite incorrect.
While the house is not a square box with a gable roof, and there are some unique features to the roof - it's no cathedral either. Nothing new under the sun. I designed a roof which I believe I, and many other participants in this forum, would be capable of making watertight, the first time. The reasons for selecting the given slope were many and complex. It was not possible to meet all the requirements and be able to use a steeper roof. For example, a steeper roof = small or no windows (overlooking a lake) on the bedroom above the roof. (One of the design requirements? - a view of the lake from every room). Or a steeper roof = small or no covered raised terrace below it. Available rise over available run gave me that pitch (after much anguish I might add). I stretched and squeezed things to come up with 2.8 in 12, as close as I could come to the 3 in 12 minimum recommended for shingles alone, and still make things work, and ice shield should make up for that shortcoming. And over an unheated area, there should be no ice damming happening at all.
In a nutshell, if a steeper-pitched roof were possible in this location, it would have been used. No aspect of the design of this house was taken lightly.
A steep pitch WAS used above an area where it was necessary to create convection cooling in the house out through venting skylights. ( I'm not a proponent of A/C !)
And there are no dead valleys here, but maybe my "valley dam" misnomer was confusing... - Aw come on you guys, give me at least a teeny weeny bit of credit will ya?
I can see that a picture or two will clarify some things. I will try to get pictures this weekend, if anyone is still interested.
Thanks again for the input - Regards - Brian.
a pic (s) would be greatMike Smith Rhode Island : Design / Build / Repair / Restore
the dead valley comments were an aside comment of an example of poor design, not pointed at your job, IMO.
.
Excellence is its own reward!
sorry Brian. I don't meean to be a putz,---but? (LOL)
3/12 was the minimum. Lets repeat that . MINIMUM
as in just barely adequate, a pube away from inadequacy----etc.
for the bare minimum to suffice----everything must work perfectly---PERFECTLY. and you missed the bare minimum of 3/12.
I have absolutely no doubt that you put tremendous effort into your design.
but in the end----you ignored the most basic purpose of a house----to provide shelter from the elements. and you valued window placement, views etc. over BASIC FUNCTION.
I don't blame you one bit,if you have too much emotional energy invested in the "design" to accept that you made a poor material specification. shingles were NOT a good choice ,functionally, for the situation you describe. there were much better,reasonably priced products which could have been installed in an aesthetically pleasing fashion. Products that are actually designed for a low pitch----that haven't broken the MINIMUM acceptable standard at 2.8/12.
BTW folks---when people say things like " shingles could be made to work here"---your kinda forcing it. I think its like telling your trim carpenter---wadda ya mean it don't fit---get a bigger hammer,it'll fit."
You've made an excellent point. Reasonably priced is not relevant if it doesn't do its job. We have no pictures, but I bet the 2.8/12 section is small compared to the roof area dumping on it. A change of materials is proper for a change in pitch. I see ice barrier as suspenders when I'm already wearing a belt.
Let me squeeze back in here.
There are manufacturers who state that the shingles may be used down to a 2/12 pitch IF certain requirements are met. One spec I remember well is to apply one layer of felt at full exposure and then a double coverage of 15# with 16" exposure. This was well before ice and water shield was invented.
It was a detail that I fely uncomfortable with as I am sure that you would. Back then, when aced with a roof like has been described here, we would hot mop a cap sheet and then run the shingles at 4" exposure instead of 5#. Likewise, there are old charts for cedar shingles that allow for installation down to at least 3/12 and I think a little below that by changing the exposure and headlaps.
I agree that these allowances from manufacturers go below what I would be comfortable with and that there are roof locations and climates that would help Mother Nature void any manufacturers recomendation. Maybe this roof here is one of those that will fail with any shingles on it, but here is my point in refutation of your argument, in part, at least.
You state that he goes below what is the MINIMUM and then base a strong arguement of condemnation on that point. But even the manufacturers have a history of varying their allowed MINIMUMS with certain other backup materials and methods. This owner/designer has speced such a method that ZI believe could work if executed properly. The main reason here for failure is less that the designer emplyed a poor design and more that his specs for accomadation of that design were ignored by a schlock shingle layer.
If I understand the description given correctly, I have little doubt that I could employ methods of installation here that would provide a dry roof for this gemntleman to accomadate his design.
Our disagreement is more of a nature of risk management. You wouold apparantly manage this sort of risk by avoiding it through avoiding the job or redesigning it or using different materials. I would manage the risk by extremely careful installation ( perfection, like you said) with backup measures for insurance.
The roofer in question did the equivalent of "borrowing" a jalopy with bad brakes and tires, driving fast it in drunken condition, and without his seat belt snapped. Any one thing was poor risk management but he managed to combine all three.
Ours arre just two different approaches to solving the problem. But we both do solve it..
Excellence is its own reward!
Andy,
Hadn't heard that one. If true then over half of the product in use in this country is in un-approved instalations.
But I would like to see a link to a quote from their literatured to put it in context..
Excellence is its own reward!
piff
The last water and ice shield I used about six months ago, gave an approved pitch (I forget what it was exactly). The job I was doing was for an historic house. It's a museum near here in a large park.
I did a small rip off attached to a circa:1760 house ( was an addition to the house I did) wood roof with about a 3:12 pitch. They "specifically" asked for ice shield on the entire roof (approx. 12x12) before I banged on 24" royals.
The woman who was on the historic commitee used to be a contractor of some kind and "insisted" on this application, so fine...nice job, beautiful location in the woods overlooking the water to the LI Sound and me up on the roof in the sun. What more could one ask for?
Anyway, the roll of ice shield specifically had specs as to the pitch. No doubt my application farrrrr exceded any warantee..but thats what they wanted and signed a contract for in spite of the warnings.
So, unless theres some specific ice shield that works on low pitched roofs which I doubt.........
Be repitched
andy
Its very hard to grow, because it's difficult to let go of the models of ourselves in which we invested in so heavily
http://CLIFFORDRENOVATIONS.COM
I guess that is their way of reducing their risk exposure.
This document from Grace shows on page five a specifically recommended low slope application in an underlying high warter volumn location. The same doc has a list of "do not..." uses which doesn't include anything about low slopes
.
Excellence is its own reward!
Piffen,
I am aware of the 4 inch exposure technique----however I don't recall the designer here indicating HE was aware of it.
Besides all the problems already outlined here----there is another big one which I am quite suprised no one has pointed out.
Let's be conservative and figure that 30 yr. shingles were used in this case.
what do you think the warranty is on icegaurd?----remember---this"design" has already broken the MINIMUM 3/12 requirement,and is FAR below MY minimum4/12 requirement. The design here is depending on a product which is simply meant to be a BACKUP---not aprimary weathering surface.
so, what's the warranty on icegaurds----and there are ton of brands on the market now---which one was specified?
would you be suprised to know that alot of the icegaurds on the market now have a mere 5 year warranty? so even with a flawless installation(which he surely didn't get here) the designer here has contrived a "system" destined to a likely failure in a few short years. his design is likely to be criticly dependent on a material which will may very well have only 1/6 the projected lifespan of the shingles.
So, this design is beating with a sledgehammer on a piece of trim trying to make it fit.
Piffen, I buy icegaurd by the ACRE, but it is a backup---not a substitute for proper flashing techniques and proper primary material choices.
I don't guess that I've refered to it as anything but a backup. That is my attitude also..
Excellence is its own reward!
Here's the picture. The basketball shows the approximate location of the leak (before the solar panels were there). NONE of the roofs above it drain onto the low-sloped roof, in fact the roof above protects the top 4' to 5' from a vertical rain. It's not clear in the picture but the part of the steeply angled roof that is below the upper roof actually slants back and under it, (it's a prow roof) so no water hits this smaller lower part at all during a vertical or even slanted rain. The valley drains into the eaves trough (what some call a "gutter"). It is important that I add that the roof leaked first during a light rain, meaning the water did not come shooting down the valley and over the trough onto the lower roof. In looking at this situation more closely now it looks like the valley between the two different opposing slopes cannot be responsible for the leak, as no rain could even have touched the steep part above it (because it is sheltered) during the leaking.
Yes, the diagonal line could have stopped at the upper roof and not continued to the the lower roof, but this would have given an inappropriate formal appearance to the house.(And it remains to be determined if this detail is the cause of the leak - being sheltered, I feel it unlikely.)
Another general point I would like to make is that I would expect that there would be leakage under occasional severe conditions under these marginal circumstances, a risk which I am willing to tolerate. I would not expect, and cannot accept that the failure ocurrs every time it rains.
I would tend to think that even some of the best roof jobs would at some point or points in their lifetime encounter severe or unusual weather circumstances which lead to some leakage, albeit maybe not to the degree or in a location of the structure that it becomes evident inside.
We'll see what the builder does.
Thanks for a spirited and informative discussion - Brian.
Sorry, dude. That roof is a classic candidate for hot tar and gravel.
If you don't want it to look that way, you can build a fake roof on top of that and shingle it for looks, but it's a PITA and a waste of money. Who the heck can see the surface of a roof that shallow from the ground? Wilt Chamberlain at the top of a slam dunk? And it doesn't look like somebody staring out that window in the stone-faced tower or whatever it is will see much of the roof either. If they do, they won't see it in conflict with anything else, so what's the problem?
Maybe the ice & water membrane would have worked, if it had been/was installed/installed correctly. But there's old technology that'll solve that problem if you can find a good installer to do it. Why re-invent the wheel?
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Dino - I don't disagree that the roof isn't visible from the ground. Appearance wasn't a problem, but it's a little late now to change.... maybe. (?)
- Brian.
When it's time to bite the bullet...bite hard. It feels better later.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I can't imagine any scenario when putting shingles on the flat roof pictured would have been appropriate.
Additionally---when the gutter on the upper roof gets clogged( they DO clog frequently yoU know!) all of the overrflow is gonna cascade down on to the lower roof.
Also, I would check out the intersection of the rake trim and the flat roof---almost directly in line with the area marked as the assumed site of the leak. I would also like to know if the upper piece of rake trim overlaps the lower piece of trim,or if it is run behind it as is very commonly done( helps hide the seam visibly from below. this can easily cause a leak---again at the rake/roof intersection----EVEN if that intersection is caulked----as the caulk is simply trapping the water behind the trim.
But heck,Dinosaur---wadda WE know? LOL!
Me, neither. As soon as I saw that picture my instant reaction was, why da F didn't somebody tell this guy about gravel...?
A gazillion brownstone and tenement roofs in NYC can't be wrong, ya know?
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Fully adhered seamless EPDM would have worked perfectly for this application. The aesthetical argument goes out the window by using that ugly black solar panel you have installed. I'm amazed you rejected the proper material being used based on appearance! Didn't you consider the appearance of the solar panels?
Also, not to rain on your parade, those shingle under the solar panel will be rotted out in 10-15 yrs. max. I've seen this on every solar panel installation that lays over shingles. Doesn't matter what type. They get steam-cooked by the moisture that accumulates underneath them. Voids the warranty too!
John Svenson, Builder, Remodeler, NE Ohio (Formerly posted as JRS)
svenny... it's a very attractive installation.. you three magpies are just killin this poor guy...
look guy.. yust like stephen said.. that high pitch rake trim termination on the low-slope roof would be my first suspect..
get the leak fixed , enjoy the house .....
and sell before the 15 years is up... seriously.. if you had axed me to roof it with shingles , i would have given you the same advice they are after the fact... but if you still wanted it.. i woiuld have come up with a shingle solution... .. maybe a mixed bag.. like EPDM under the collectors..
anyways.. good looking house...
i figger everyone should design and build at least 3 before tehy get it right.. and then they have to sell it to downsize anyway...Mike Smith Rhode Island : Design / Build / Repair / Restore
"i figger everyone should design and build at least 3 before tehy get it right.. and then they have to sell it to downsize anyway... "
crap, you mean I'm not done..............
well, I know I didn't finish, but I did think I was done.
crap.Remodeling Contractor just outside the Glass City.
Quittin' Time
If that's the case....I never plan to ever get started!
Keep telling Cath ...stop dreaming.......we're never gonna live in a new house....
there's way too many old houses I haven't fixed yet!
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
Well gentlemen- It's been a long few days. Here are closeups of the edge of the prow, the valley of the upper roof where it meets the lower eaves trough, and the area where the prow fascia meets the lower roof. They do look reasonably sound (at least in a light rain) to me.
I have to remove a section of soffit for access to confirm that some work that the roofer has done since has solved the leakage problem.
A conflicting observation- After years of exposure shingles under a solar panel such as this one have ended up looking like new ones compared to uncovered ones next to them in this locale using similar panels. Slits every 4" or so, plus the wrinkling from expansion prevents contact with the roof intimate enough to cause moisture trapping. This is one ineffective vapour barrier.
Regards - Brian.
ps. Dino - je ne sais pas. K's P gasket???
Thanks for the photo. That puts things in a whole different light.
If you had called me to repair your leak, the FIRST thing I would suspect, regardless of the material used on the low pitched roof, is the detailing at the valleys and roof edge that I have indicated in the return photo.
I see no drip edge on the fascia to prevent water from bleeding back. That is critical in a place like I have outlined in purple where a high volumn of water from the upper valley can follow that edge.
I cannot see how the bottom of the cvalley is trimmed out. I either hang over the drip edge by an inch or two, or more commonly, I seal and hem it back onto the drip edge. You could have water from bottom of that upper valley wicking under the vally and down the back side of the fascia until it hits the lower roof where it gains entry.
and again, the base of that fascia must be carefully detailed with flashing, none of which is apparant in the photo. All that shows is a tightly caulked fit. caulk there can hold water and encourage it to penetrate the system. I leave the fascia cut an inch above the shingles in such a location.
Question - is this fascia clad in AL? if so, did the siding AL guy do the flashing for it or the roofer?
My guiess from the appearance is that you have AL covering fascia and it lips up with no drip edge under shingles. The fascia is scooping water and diverting it to the base where it enters under the shingles, to find a way in a littel further down. If I am right, an EPDM or BUR roof material could still be leaking.
Another item to check is the actual pitch. You designed it at 2.8/12 but it looks like a 2/12 to me, tho I realize that looks can be decievint in a perspective view like this. Sometimes the framer doesn't end up with exactly the pitch shown in drawings for one reason or another..
Excellence is its own reward!
Piffen,
around here that detail with the rake coming down and setting on the top of a lower porch roof is pretty common on a lot of older houses.
Usually ,due to the local framing and sheating style on the old houses we can very easily lift up the bottom edge enough to slip a shingle in place underneath.
In the case shown here----I would have insisted on EPDM and very easily been able to get a continuous piece run clear back under that rake,the entire overhang and coved to the wall. It would have been absurdly easy, especially if I got there before the aluminum trim guys.
At that point, my only worry would be the siding guys walking around on my nice new rubber with a nail stuck in their boot, or the rubber getting cut by a careless installation of rake trim.
but hey, not my problem,no?
Nope, nor mine. I think we agree that therre are multiple possible points of entry beyond what was first mentioned in the tectual description. A picture is worth...
.
Excellence is its own reward!
Raining up there also piffen?
no, I'm working on a house design on the CAD.
Excellence is its own reward!
Thankyou all for your input. I should be able to post a few closeup details of the specific areas in question within a couple of days.
Regards - Brian
ps. If I can get this roof to the stage where it is waterproof then hopefully I will be able to put off biting the bullet for a few years.
Um, you did say this was the roof of a breezeway, right?
If that's the case, have you ever heard of a King's Point Gasket ROFLOL!
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
"...I stretched and squeezed things to come up with 2.8 in 12, as close as I could come to the 3 in 12 minimum recommended for shingles alone..."
Sounds like you might have been better off to do less "stretching and squeezing" and live with a low slope not visible from the ground and use EPDM or other alternative instead of shingles.
Rich Beckman
Loving that 20/20 hindsight (Hey! it's the only direction I can see anything!)
Don't count on metal roofing to solve leakage problems on low-slope roofs; I see (and correct) it all the time. Most of the leaks come from faults in installation--like no butyl between laps, or screws overtightened then backed off--but the material is working maxed out to keep leaks from happening at slopes that low. There's no design-state slack left; any minor imperfection can lead to leaks. That's too critical for the real world, IMHO.
I'm no fan of pre-fab ribbed metal roofing in general; I find the fit on a real roof unsatisfactory no matter how carefully we do our work--, and, as I said, marginal for its purpose once you get below 4 or 5 in twelve. In a complex roof, it's a friggin' nightmare and I won't touch it.
On this thread, I agree with Piffin, Mike and co. Shingles should be able to do the job--but they also are maxed out and need help. Really well done flashing, judiciously placed 'pitch', and a glue-down membrane fully covering the roof and up the wall onto the flashing are minimum.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Dinosaur,
I may be wrong----but I believe that you are envisioning a completely different metal roof than I am. I would have to agree with the limitations of the metal product you described.
I am thinking of a system I see frequently on old houses in this area. Usually heavily painted 90 year old galvanized---I think the term is Lock Seam. I find it all the time in porch/window well intersections.
Okay--I think you're talking about soldered standing seam roofing. That's a type of roofing that's got my respect--and awe. I tip my beret to those who can do that kind of artistry.
The crap I was talking about is yet another modern fake that purports to replace the older technique with something any idiot can (and often does) slap up in a jiffy. Everytime I accept a job to install this stuff I regret it: I do as good work as anyone else and better than lots, but I can still never satisfy myself with the quality of the job even though the customers are happy. The material just doesn't adjust well to the real world of out-of-square roofs. Next week when I've got a bit more time, I'll be posting a new thread I may call 'The Roofing Job From Hell' with photos of a nasty job of metal roofing we finished earlier this summer. The photos won't show the defects that bug me; but I'll tell all anyway. There are some useful technique angles in this job, though (the roof was 25 in 12 and we had to insulate it on the outside, to boot...).
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
dinosaur---I will look forward to your thread on the roofing job from hell.
I am always eager to learn more about roofing----the more I learn,the more I find there IS to learn.
I agree completely.
A "good design" for a roof wouldn't need special precautions to back up the standard system. Not that a borderline design can't be made to perform....
But the best roof design take function over form.
Jeff
Buck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite