Flat roof application- residential home
Hi to you all,
My name is Gur and I am an ISRAELI guy who had moved to Fort Worth TX two years ago with my wife .
My wife and I will be staying here for few years and these days we are in the process of building our own new custom made home.
My questions today are regarding flat roof applications….
Back round: Our house( one story high) is designed to have a low pitch roof ( 1″x12″ pitch trusses located 2′ on center) on the entire house area. This roof is going to be surrounded by 3 ft parapet walls .
These days I am trying to figure out how to characterize the roof system (technically)so these are my questions:
1. Does a 5/8″ OSB decking is the way to go here ? , or do I need different decking material ?
2. Do I need to locate the trusses 16″ on center in order to prevent the OSB from bending/sagging ?
3. What will be the best roof system to go with (EPDM, foam, liquid,) as for preventing /decreasing the chance for future leaks? and easy to patch /fix in the future? and budget wise of course.
4. What is the most tested and satisfying system here in the USA for flat roofs?
I will appreciate if you guys guide me to the right direction.
Warm regards
Gur
Replies
You should contact a commercial roofing firm in your locale for their recommendations.
View Image
"A stripe is just as real as a dadgummed flower."
Gene Davis 1920-1985
He might do better with a residential firm. A lot of the ones that do commercial don't want to be bothered with residences.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
You're right. He is in a big metro market, and the roofing outfits that do commercial simply don't cross over. That's my read on DFW.
Here in our mini market, they do, and the two commercial roofers I know would offer good advice on a job that small.
My suggestion to talk to a commercial outfit was biased in the sense that the residential roofers here would be clueless about a flat-roof-with-parapets job.
I just did the "overwatch" as a board member for our little museum, on a tiny vestibule addition that had a roof like that being discussed. Sloped roof insulation, membrane, coatings, parapets, parapet caps, etc., all handled by one of our commercial guys.
View Image
"A stripe is just as real as a dadgummed flower."
Gene Davis 1920-1985
It is actaully a fairly common roof style in the SW, so 2/3s of the roofers would be able to handle it is my guess. That is of the reputable real roofing companies, not the hail hounds and gypsies.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I notice that your plans say "owner builder network" on them. Do they have any guidance for you for finding a roofer there in Fort Worth?
You will definately want to engage a professional roofer for this job. My advice would be the sooner the better to get bids and head off any problems.
Hi to you AQUAREPE4,
The owner builder guys are great!!!, and they do have great list of contractors (in this case roofers) to work with as long as you stay on the conventional roof system route, in the minute that we came up with a different residential request like the flat roof it was hard and almost impossible to find here in Fort Worth the contractor that would be able to give us the right solution and to back it up with some past experience with it.
Flat roofs are more popular in southern texas and western texas, but I would think you could find someone close to help.
Gallagher in Ft. Worth does flat roofs. More of their work is commercial, but that do residential, too.
There's also a flat roof guy named Jaramillo in DFW. Goes by SJ.
There's a pretty prominent flat roof guy in Houston. Rayburn is the name of the company. If they can't help, maybe they can point you to someone in central or northern texas.
If you want, I can dig up contact numbers. I have some contacts for subcontractors in texas that I could tap.
I would also email Owner Builder Network for help. Gary Kramer is the owner -- i bet their Houston franchises have more contacts on flat roofs and they can help you find someone good.
Hello and welcome GUR,
definitely not foam, IMO For multiple reasons. It is a great insulation when used inside, but problems abound when used as roofing.
EPDM is the material of choice in my experience - this coming from a guy who did roofing including BUR for twenty years.
For the sheathing, 5/8" is fine IF it is T&G to avoid flex at joints which will put a wearing on any roof material. You probably don't ne3ed to worry about snow loads so 24" OC should be OK. I [prefer the Advantec brand of OSB. It is much stronger and more water resistant.
I would use a buffer material for underlay under the EPDM. There are several available so I don't know what is common down there. Basically itr is 4x8 sheets about 3/8" thick of a fibreglas and gypsum to nail down to the sheathing, offsetting the joints from the ply joints. Then the EPDM is glued to this underlayment. Usulaly done by the roofer at time of installation.
For some reason I have not been able to view your pdf. But that could be my connection.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Piffin hi,
Thank you for your thorough answer, I really appreciate it.
Does OSB clips are a substitute for the tongue and groove method?
How do you seal the 90 degrees corners along the parapet walls, and the roof penetrations such as air vent ducks or the openings for the scuppers?
Do you think that working with EPDM system can be reliable enough for the years to come ( the summer in TX brings 95 f degrees in average, and the winter is showing somewhere around 40 degrees)
Do you have any supplier to recommend for a turn key EPDM system materials?
Thank you again
Gur
You can get EPDM in white, and it can be painted with latex. As Grant mentioned, UV is what will age it. A white latex roof paint can shield from that. EPDM is incompatible with bituminous products though. clips do fine on pitched roofs, but I don't think they give you what you need in stability for flat workIt sounds like you are trying to do this yourself with your other questions. Detailing so much is too hard to answer in a forum like this. You would need a class.
Mulehide is a provider though, and I think they have instruction manuals.But the scupper detailing will be the trickiest and I advise a pro with good references.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I missed the point on the corner breaks. EPDM is flexible enough that it can handle that fairly well, but the common solution there is to avoid a 90° break by installing a cant strip. This is a 2x2 ripped with 45° bevels to go in there at the break and soften the curve up
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
You can buy pre-made cant made from the same material as the recovery board.View Image
Yeah, I knew that, but have made so much of my own on BUR jobs, and this guy sounds like he is trying it all DIY...But the premade is far better. No splinters to deal with.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I feel that there is some lack of clarity when you are talking about flat roofs, roofers and material suppliers know the terms or the existing methods but don't know to give answers when it comes to details.
As a guy that had a lot of experience with construction in Israel I find that getting into the little details and asking for clarifications is the right way to get the right results and it also helps to determine how knowledgeable and experienced the guy that you are going to hire.
To be honest with you, if I won't find the right guy for the job I would probably adopt the do it yourself method, but before getting there I am trying to be on top of all the weaknesses that this roof system brings.
I will still search.
It is nice to get your comments, thank you for that.
Gur
"I feel that there is some lack of clarity when you are talking about flat roofs, roofers and material suppliers know the terms or the existing methods but don't know to give answers when it comes to details."Your lack of complete sentence structured or confusing grammar and punctuation in this sentence leaves me unclear if you are speaking of me personally or using the word, "you" generically. Is there something you want ME to be more clear about?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Not to step on your toes here, but a spray foam roof might be better in his neck of the woods. I'm not saying it IS the right choice, but it's possible that the problems you've had in your area don't apply to his area. A product that seals AND insulates in that hot Texas sun has to be worth a pretty close look.Rebuilding my home in Cypress, CAAlso a CRX fanatic!
Tu stultus es
The problems I've seen WERE in his neck of the woods!;)to be fair, it was a long time ago, and one poster here once told me that they have solved the problems now.But one of the problems is that the quality of the install depends greatly on the skill and experience of the operator on job. and the franchisers sell this to anyone, regardless of roofing experience.So a lot of the installers are the get rich quick crowd who do not focus too highly on the detailing, which is one of the most important things on a roof of this kind and style.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Amen on that!Rebuilding my home in Cypress, CAAlso a CRX fanatic!
Tu stultus es
I've always used this with good success in residential - http://www.sealoflex.com/
Search sealoflex in the archives here and you'll find some of my threads pimping the product.
Forrest
I'll pretty much second Piffin's suggestions except to note we're both way out of your region. You've got more intense sun for longer periods of time and that's the nemesis of EPDM. I'm not sure TPO would fare much better, but I'd suggest white EPDM or TPO. They both install pretty much as Piffin entailed.
The devil is gonna be in the details on this roof. Since the entire roof is parapeted, the scuppers thru the parapets are going to be the weak link and an easy source for unseen damage until it's too late. I see nothing is actually specified as far as the scuppers, so the archy is leaving it up to the roofer to do the design work on them. Chose your roofer accordingly.
View Image
Sounds like the perfect application for a green roof. I'd imagine DFW is pretty miserably hot in the summer.Not that a green roof has anything to do with roofing material choice...Z
Good point on the scupper detailing. I read his mention of 3ft parapet walls as having the walls on only three sides - three parapet walls.<sheepish grin>My Adobe is trying unsucessfully to do an update and hitting server problems. This PDF must be a newest version kind of thing.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
FWIW. I am a resident of Ft.Worth, Tx. I used to have a design/build company. Now just design. Since I have retired from the building part (I like be where there is central heating and A/C) the roofers that I used, like me, have retired or have passed on to that great melting (tar) pot in the sky. Roofers around here come and go like the tides, so one has to be careful.
One of the most dangerous things one can do is recommend a sub. However I have a friend that has a large State Farm Insurance Agency here and uses a particular company almost exclusively for their damage claim work. I designed his (the friend) office building, his personal home and his two daughters homes. This roofer did all of the work. I have not use this roofer personally,so I can't give a first hand recommendation and have no contacts within the company. All I can say is that they has been around for a long time. Contact me if you wish the name of the company.
It is true, around here, there is not a lot of low pitch residential construction. A little slate and clay/cement tiles, but mostly comp. shingles.