Help redesigning exterior wood stairs
Please, can somebody help me figure out how to build an outdoor stairs that won’t rot right away?
I have a San Francisco Victorian wood frame house with a wooden stairs in front. It’s just a straight half-flight of stairs, with wood risers and treads, balisters and newell posts. The treads are fully housed on both ends. Howver the stairs has started to rot badly and needs to replaced, and I want the replacement to last longer than than this one (replaced less than 10 years ago). Can anyone suggest an approach that would still look traditional and yet be better designed from the standpoint of protecting from the weather (which, in this climate, is obviously rain rather than snow and ice.) I don’t want to use synthetic or engineered wood products in places where they would be visible. Here are a couple of things I’m considering:
1.) As currently built, the risers and treads butt into the housing (or is it called casing?) on both sides, so when the paint film & caulk is compromised, water gets right to the end grain on the risers and treads, and they just wick it up and start to rot. I wonder if it would make sense to make a hidden sub-structure of pressure treated stringers, have the risers and treads sit directly on these, so their end grain is always exposed to air, then wrap the whole sub-structure with redwood in a way that the underside of it breaths but is protected from the rain (I don’t care about the cosmetics from the underside; that part is hidden.) Of course that would mean I need to route out the inside plank of the casing assembly so the treads go past it and not butt into it.
2) Where the bottom of the stairs hits the newell post it creates a little angled area where water can pool; I’m thinking maybe I need to put a small triangular frog in here, or maybe some kind of flashing, to divert the water away.
3.) Is heart redwood the best wood to use for this, or is there something else that would better resist rot, perhaps be harder than redwood (for the treads, which get a lot of wear) and be paintable?
4.) A lot of the houses around here use a heavy membrane type of surface on exterior stairs and landings; I’m not sure what it is but it doesn’t look very nice or very consistent with the period. What is the most durable way I can finish the stairs — what kind of paint — while still keeping a roughly appropropriate period appearance?
I apologize in advance if this is unclear due to any misuse of terms on my part; I’m still learning this stuff. If this is totally confusing I can try to post a digital photo of the current stairs so you can see what I’m working with.
Thanks in advance.
Replies
Yep, post a pic or two or three. be sure to do .jpg, and size down to 50-100kb
In suburban New York where I grew up, porches, called "stoops" were made of masonry. Because I wanted zero maintenance on my new home, I used masonry there.
Here are a few photos. The porch is in the Arts & Crafts style, not Victorian as your home may be, but you might be able to use masonry and restyle it to suit your architecture. You have the advantage of not needing to go deep with your footings because of your mild climate.
David,
Here are a couple of pics that may offer you some notions about yours.
As you can see, I kept the newel posts on this porch off of the bottom step and free of contact with it. Those posts are made secure and anchored to the concrete with a tension rod that is held on the bottom to an elevated 1/4" metal plate that is fastened to the concrete inside the hollow base. There are four "upside down" stainless steel bolts that protrude a bit from the bottom of the wood base. Turning those protruding heads with a wrench allows for plumbing of the post and keeps it out of the water which is what I like to do whenever possible. The top end of the threaded tension rod passes thru another metal plate under the cap of the newel post. This is where you tension the rod with a socket and ratchet.
And yes, I laid the flooring against all "the rules". It runs parallel to the house and is comprised of dead clear CCA SYP that I tongue and grooved myself. I don't always care for the look of laying the flooring perpendicular to the house wall when the run is as short as this would have been. Actually, it isn't any different than the steps, so if it works there………? Since this is CCA, I decided to take the chance and it gets faithfully treated with water repellant every other year. It's been in place for over ten years now and nary a sign of any problem.
The stair tread and risers shoot over the outside stair horse on each side by a couple of inches, I believe. There's four stair horses under there, by the way. I think you indicated that yours was not, but all this stuff needs to be CCA as far as I'm concerned. The sides of the porch deck itself and the undersides of the horses are closed off with framework and lattice.
You'll notice that I used 2"x6"s for the bottom rail of the railings and balustrade. This piece is "gabled" if you will and each baluster is "birds-mouthed" to sit down on it. I've never thought that the frequently seen square-ended balusters sitting on a flat bottom rail was anything but an encouragement for water wicking, rot and paint degradation.
(Yes....….I made those storm doors, too.)
Nice work!
Thank you for the compliment.
Like everyone here, including yourself I'm sure, I try to do the best I can in my judgment with any given situation that's presented. And I will admit that I like the way that one turned out.
Knowledge is power, but only if applied in a timely fashion.
I liked it too.
You beat me to the draw several times, justy not on this one.
I think the full width exterior stair tread is more common where there is no freezing weather. Let a little frost or ice form on that painted thing and you've got an unplanned visit to the emergency room..
Excellence is its own reward!
"You beat me to the draw several times, justy not on this one."
And my feeble brain may require a day or more to come up with a proposal......in my spare thinkin' time, you understand. :-)
Knowledge is power, but only if applied in a timely fashion.
Beautiful work, and thanks for the reply. What is "CCA" - is that a preservative treatment? I'm familiar with PT - "Pressure Treated" but the nasty gashes that are made in the wood to inject the preservative make it unsuitable for any place where it will be visible. Thanks.
By the way, I just heard that there is available an exterior grade MDF in 3/4 inch thickness. Any thoughts on whether this would be suitable for vertical exterior surfaces like risers and newell posts?
CCA is one type of pressure treated, probably the one you are thinking of. It's the most widespread method, the one used all over for years. It stands for the chemical used, chromated copper arsenate.
The newer treatment, believed to be safer, is ACQ, which stands for alkaline copper quarternary. Apparently as it's new on the market, people are discovering that it's extremely corrosive to certain metals, including, significantly, steel nails and hangers. There will be much written about it, I'm sure.
"I'm familiar with PT - "Pressure Treated" but the nasty gashes that are made in the wood to inject the preservative make it unsuitable for any place where it will be visible."
Huh? What gashes is that? Where you buyin' your PT from? :-) Never heard of such a thing nor saw it.
Basics of PT, as I've witnessed, is that the lumber is stacked on a cart, rolled into a pressure treatment room/box, stainless steel, I believe........the doors are closed and sealed. The liquid treatment solution fills the container and is then pressurized to force said liquid deep into the wood for a predetermined amount of time. Tank is then drained and the wood cart then removed. No gashing nor gnashing of teeth, either.
As far as exterior MDF products go........I'm old fashioned and use real wood. I just don't trust the exterior MDF stuff and since I stand behind everything I produce, I don't need any nasty costly surprises. When and if it proves itself over the long haul, I'll consider the use of such.
Edit: If you havent visited other threads currently running, you might want to read this one for others usage and feedback on exterior MDF products and similar.
http://forums.taunton.com/tp-breaktime/messages?msg=34986.1
Knowledge is power, but only if applied in a timely fashion.
Edited 9/24/2003 3:02:42 PM ET by GOLDHILLER
Left coasters and the rest of the U.S. should never discuss PT lumber, they are two different animals.
In the left coast they use douglass fir and the treatment does not penatrate and thus they have to incised the surface to get the treatment in.
The rest of the U.S. uses syp, like God intended <VBG>, and it soaks of the treatment.
GoldHiller, I don't know if I'm just shopping in the wrong stores or if this is something unique to california's environmental consciousness, but the Pressure Treated wood I see out here is not the greenish copper color stuff but brownish stuff, and it is definitely knifed by machine. It's not what you want in a finished surface. I've enclosed a jpg so you can see what I'm talking about.
I've also enclosed two shots of the rot. These are really ugly. One shows that where the risers and treads butt into the sides of the housing, the end grain has wicked up moisture causing all three pieces to rot; the other shows where the housing meets the newell water has penetrated rotting out both parts.
Any further suggestions, anyone?
Question - did you paint and prime all sides the tread before assembling?
End grain likes to wick up water, so wick up some paint on the end grain. Dont attach, butt or connect any bare wood, paint it ALL first.
From: Sungod "did you paint and prime all sides the tread before assembling?"
This work was done by someone else, but by the looks of things I'd say probably not.
I feel a long post coming on with lots of ideas for you to bounce around in your head. They don't all necessarily go in the same direction.
First, I'll describe what I do here.
I use PT framing lumber for the stringers.
leave the underside open.
Run 1x4 on the treads - either clear vertical grain fir or Ipe`. The slots let the rain through instead of puddling it to cause rot. I run them over at the ends instead of housed.
The risers are either open or pine typically. When I use pine, I prepaint it on all surfaces and use gorila Glue for the mitre joints along with nails.
The top surface gets oiled every couple of years or Thompsons on some every year.
I have some done like that dating back to '88 that are still in good condition - this is Maine where humidity and rot are a fact of life.
Now, I'll comment on yours.
I think the design is what causes the rot. Start with the treads. A solid tread is intended to hold water. It is especially efficient at it when the ends are housed instead of open. You can't even use a broom to swipe off the morning dew.
The other problem with solid housed treads is that they swell and move with the moisture. That will break any glue or caulk joint where it meets the vertical surface.
They are painted dark. This one may just bee an old wifes tale, but painters here swear that darkly painted wood trims on exteriors will rot much faster than white. The heat of the sun it collects keeps the moist wood under the paint a few degrees warmer on the average, making a more hospitable home for bacteria and fungus.
But it is a beautiful design and I know it might be hard to go against neighborhood standards and all.
So if I were asked to build a stoiop like that, here are some things I would consider;
I would definitely use PT for structural frame lumber. Since your west coast fir PT is reportedly inferior (GD&R) I might recoat it after all cuts with a preservative solution of some sort. To make the housing trim, I would use CVG fir and seal it on all six sides. I might try to design the shoe the hoiusing fits to as aframe that is open under and inside to breathe a little. I don't know if yours is all solid of framed and dressed in.
I would make the treads out of CVG fir and seal it and all sides.
When joining the fir to the housings, I would use West system epoxy top make up the joit with screws from backside. If this is too much of a logistical problem, I would at least dry fit everything and then seal the end cuts of the treads and the dadoed housing with the epoxy to prevent it from wicking water up.
The risers I might try to do so they rise about a quarter inch off the tread to let air and ater flow. The exterior mdf you mentioned is called MEDEX tradename. It is similar to Georgia Pacific's Primetrim. I have used both for very wet locations of exterior trim and find it very good at not absorbing water or rotting. But I am aloof to use it for locations like this where toes and heels can scuff it. It is so hard that it chips easily and that will leave a poor appearance after a few years IMO. It is also a little hard to work with, needing predrilled holes for the stainless nails. A nail gun laeves little volcanoes.
So I would use cedar, red cedar, or redwood for the risers, pre-primmered on all sides, of course.
Maybe some of this will help a little.
.
Excellence is its own reward!
Thanks to all, especially to Piffen and GoldHiller for the helpful -- and in some cases very extensive -- suggestions. I think I've got enough ideas and suggestions to give it a shot. What a great discussion board this is! You are all very generous with your expertise.
David,I believe, (someone will correct merif wrong) that treads can be a little out of level, so why don't you build in a 1/2% (1/16":12") slope?
And my brain doesn't work good 'nuf to compete with piffin and co.
SamT
Well, I chewed a bit and will now regurgitate.
I think the stringer and stair design under your circumstances and probably in general is best kept to concrete and could be done that way if you so choose. The balusters and handrail of course could still be wood. If it were mine, I'd seriously consider some concrete for the most vulnerable areas……..this includes the treads.
That 'boxed" arrangement is fraught with moisture problems and even more so when the stringers and newels are left sitting down there in the water, as evidenced by your latest experience. Even if you could get God's rightfully intended treated wood for this project and build it as a duplicate of what's there now, you'd still wick water and throw paint. If you want to give that a go, those of us out here won't tell if you make the necessary trip out of the Devils lair, acquire some good wood, and then paint it prior to returning. That way the border patrol won't recognize it hopefully. <g>
All that being said, I did play with some ideas of how to pull this off with wood and Trex.
Fortuitously, this concurrent thread to yours has a pic and some info about Trex being used for a railing and it was painted.
http://forums.prospero.com/tp-breaktime/messages?msg=34964.1
And so, here's a little simple drawing of some of my ideas. Basically it consists of a methods to get the bottom of the stringer off the concrete via a sandwich of treated stock in the center and then either wood of your choice for the show part or the use of Trex for that. You might consider Ipe, teak, cypress or similar for the show wood to help resist rotting. Treads also would be of this rot resistant wood. That approach is still apt to leave you with failing paint from the wood wicking water, but potentially much less rot factor.
The potential downside to the use of those woods is they may not want to hold paint worth a hoot and so you could find yourself refreshing the appearance every several years. Redwood, by the way, is just too soft for stair treads IMO.
Now if you were to consider the use of Trex (painted or not) those wicking areas become much less problematic. You would have to stick another stairhorse under the Trex treads though as it requires more frequent support. That's no biggie to do. All stairhorses would be of treated stock, of course.
You can see I've added a little gabled piece to the stringer cap for the balusters to sit on and where said piece contacts the newel post, it will double as a cricket there to shed water quickly away. Two approaches to connection areas………..either try to caulk them tight with something like a quality polyurethane caulk or leave a space between them so that any absorbed water can dry out again. I usually accomplish the latter with a couple of washers for spacers. While this may not look like the consummate tight fitted joint, but it sure beats the heck out of having things rot away in a hurry. Although if spaced off the newel for instance, I'd make sure to well seal the endgrain prior to mounting.
Checked the books and those shots I posted of that porch were taken 12 years after erection. Original paint job. That means I've only got 38 years to go with my 50 year challenge. <G> I honestly think it'll go 75 years if given a bit of periodic care via that water repellant.
Your last post sounded kinda like you checked out of here, so if you don't reply via the board here I may just e-mail my musings directly to you.
Knowledge is power, but only if applied in a timely fashion.
Goldhiller, thanks. Those are excellent suggestions and I really appreciate the cross sectional drawings. The key lessons I'm taking from this are:
- use the right wood, esp. PT wherever it doesn't show
- protect the end grain by pre priming and preferably avoidng butt contacts and otherwise caulking the **** out of it.
- pre-prime and pre-paint everything before assembly wherever possible.
- use a cricket and/or cable profile on the top of the housing to shed water and not let it pool where the housing meets the newell
- get the post and stringers off the ground somehow so they don't sit in water, especially the end grain on the post.
- since I don't want to give up the housed tread design, I need to find a way to get the water from pooling along the back and sides. I like your idea about using washers as spacers; it's pretty subtle and does the job.
Just a couple of quck follow up questions: do you find that Trex holds the paint well enough to continue to look wood-like after it wears? And is one standard washer thickness enough of an airgap to be effective?
Thanks again. This is very helpful.
David
Sounds like you're definitely getting a handle on the principles involved which are simply....... keep it as dry as you can by whatever means you can and provide for drying out.......and use rot resistant materials because nothing is perfect.
"Do you find that Trex holds the paint well enough to continue to look wood-like after it wears? And is one standard washer thickness enough of an airgap to be effective?"
I have NO idea how well Trex holds paint as I've never personally done it. Specialty primer like XIM may be in order.....probably is. I've seen it used in post threads here for window sills and such and these were painted. That's all I can say on the issue. I think Mike Smith and Piffin have both done this, so they'd be apt to know more in that regard. It has been recommended here, so I think it probably works fine or at least the tradeoff between more frequent painting and having no rot is a no-brainer. By the way, Sherwin-Williams offers a paint called Shark Skin or Shark Tooth or something like that which gives great grip underfoot. Used it once on some basement stairs. Don't know if it's available in an exterior formula but I would think so.
"protect the end grain by pre priming and preferably avoidng butt contacts and otherwise caulking the **** out of it."
You don't have to avoid tight butts, it's just that if you go for it (as one usually does) you just have to make sure that it is indeed tight to prevent water infiltration. Say where the handrail meets the bottom newel post. I know a bit of water will want to there unless a little cricket is made and installed. Whether I'm going for a tight fit or a gapped connection .......I'll usually soak the end of that handrail in water repellent for several minutes, let it fully dry (so you need to plan ahead and be patient), prime it. Then frequently if going for a tight fit, I'll also butter the end with a thin coat of polyurethane caulk immediately prior to drawing the assembly together. Then remove all the squeeze out. PL brand poly caulk is the easiest for me to grab here, has never disappointed and is paintable. (This is all similar I think to what Piffin suggested using West Systems for. Principle is the same.....prevent water wicking up the end grain)
If going for the nice tight fit, the application of that quality caulk around those joints can't be overempahsized.....on a fully dry base. And the maintenance of it can't be overemphasized. With a quality caulk, there's very little of that as the years go by. ,p>
If at some particular joint, I decide to make a gapped connection, I like to see betweem 3/32" and an 1/8". Which joints? It depends. Kinda of a judgment call based on experience melded with individual circumstances.
"use a cricket and/or cable profile on the top of the housing to shed water and not let it pool where the housing meets the newell"
Yes. And the use of a continuous gabled area on the rails/stringers also benefits the balusters from the same desire to pool water.
"get the post and stringers off the ground somehow so they don't sit in water, especially the end grain on the post."
This is an absolute must in my book unless they're made of concrete or other non-effected material. And the end grain of that stringer and/or the stairhorses are just as vulnerable. Don't leave those sitting on the concrete either. ALL endgrain is especially vulnerable and needs to be considered in design and maintenance.
"since I don't want to give up the housed tread design, I need to find a way to get the water from pooling along the back and sides. I like your idea about using washers as spacers; it's pretty subtle and does the job."
Use of spaces and washers concerning the treads and/or risers will need to be carefully considered, I think. Usually one is depending to some degree on the connection between these pieces to produce a strong, rigid cohesive unit in a design such as yours in the pics. You might consider the following: place one "extra" stairhorse tucked just a couple of inches inside the end of the stairtreads, so that you're only using the outside stringers to support the handrail assembly and to look pretty by closing off/capping it visually. Then you can afford structurally to leave gaps between the end of the treads and the inside of the stringer/handrail/balustrade assembly.
Leave the underside of all this open if at all possible. Things need to breathe freely if they're going to dry out.
"use the right wood, esp. PT wherever it doesn't show"
I use CCA PT for show all the time, but then we've got the good stuff.
Knowledge is power, but only if applied in a timely fashion.
I've had some experience painting Trex. All the window and door trim on my house is Trex, installed in 1999 and painted in 2000. None of it is walked on, though, it's all around openings. But, there is no degredation at all, no peeling, no blistering, and I can't scratch it off without cutting it.
It was painted with 100% acrylic primer, with two coats of 100% acrylic paint. The house is in upstate New York, on the Canadian border.
Thanks. That's good to know. Now I have one more weapon/piece of knowledge in the arsenal.
David......just so there's no misunderstanding concerning the drawings and my suggestions......
That triangular piece you see sitting on top of the stringer assembly is intended to be one continuous piece that runsunder all the balusters as well as butting the newel post(s).
You might consider making a little individual one where the handrail meets the newel as a long continous one there isn't necessary and wouldn't serve well under one's hand. I rarely do, but rather just make sure I have a tight or breathing joint there.
Two little ones could be made from cutting one properly sized small pyramid in half.
Edit: If you're thinking of leaving the tread ends gapped from the side stringers, I'd make that gap worthy of its' intended purpose.....maybe 1/2" Better drying that way and big enough to allow the periodic re-application of a water repellant on that vulnerable tread and riser endgrain.
Knowledge is power, but only if applied in a timely fashion.
Edited 9/26/2003 11:26:59 AM ET by GOLDHILLER
Many thanks for the additional comments & suggestions. One final (hopefully!) question.
".......I'll usually soak the end of that handrail in water repellent for several minutes, let it fully dry (so you need to plan ahead and be patient), prime it. "
What type or brand of water repellant do you use for this? I believe that some types of water repellant such as are commonly used for redwood decks, are not compatible with exterior latex or acrylic paint, so I want to make sure I'm using the right stuff here.
Thanks again; you've been most generous with your time and expertise.
Well , this oughta make many here grimace and think me an idiot. That's okay, many do now.......what's a few more?
I usually use the paraffin-based product (different from the oil-based product) …..( Oh God, here goes).….from Thompson's Water Seal. When dry (give it plenty of time), it readily accepts an oil-based primer and has served me well for years in this regard and application.
I realized after that soaking suggestion that I hadn't specified, but you caught the omission, as you are evidently knowledgeable about water repellants and paint compatibility.
So basically, after chasing around the mulberry bush in every conceivable direction designing your steps in the quest to keep them as they basically appear now and still make them from wood while preventing degradation and rot........it seems I'm kinda at...... build the stairs as a separate entity from the side units. Those units would serve as support structures for the balustrades only and as "visual closure". This would allow you to keep the three units separated from one another by 1/2" (even an inch wouldn't look out of place) for draining, dry-out and easy replacement of individual parts if necessary. Also keep any wood up out of the water on the concrete and you should be good to go.
While this may have a slightly atypical appearance in some ways, it will hopefully avoid the rot problems inherent in a conventional wood construction approach.
I'm sure you've realized that you could use a Trex block (or similar material) for the elevating of the newel post, but those SS bolts in threaded inserts provide for super easy plumbing. I'd be mighty surprised if the concrete is dead level eliminating the need to adjust for plumb.
Knowledge is power, but only if applied in a timely fashion.
Thanks, Goldhiller - I'm glad I asked; I would never have thought of that particular product. I like the idea of basically separating the two structures. I'm even thinking of putting a small bevel, say 15 degrees, on the end of the risers and treads, making them look a buit like quoins (corner blocks) fashioned out of wood to give the appearance of dressed stone blocks. This is different, to say the least, from the original design, but still traditional, in a way.
I'll post some photos when it's done.
- David
"I'll post some photos when it's done."
Please do. As a matter of fact.....you damn well better. I'd like to see your particular alterations and tweaks.
Hope I catch 'em when you post. Or you could always make sure I get to see it by e-mailing them. (hint,hint) :-)
Knowledge is power, but only if applied in a timely fashion.
The US Wood Forest Lab recommends what they call a "paint water repealant, protectant".
It will have some anti-fungal material in it such as copper naptha.
Thanks for the pics and for having them so nicely sized for download.
Well, it would seem that Bill Hartman has already covered my "misunderstanding" about PT wood on the west coast. Open mouth wide.......insert foot. <g> Or maybe it's more like having your pants fall to yur knees in a public place. But at least I learned something that will hopefully prevent another occurance of that. I guess the biggest reason I come here is to learn something, so today was a big success.
And yes, that's some ugly rot going on there. I'm not quite as quick on the draw as Piffin is, so I've got to think on that a bit before offering what I might do. But...........I will say that I don't particularly like the look of separated boards for a stair tread or a porch deck (although I've built a few that way any hoot) and I find/feel that it looks really out of place on a vintage home.
I'm willing to bet that my t&g CCA SYP porch deck and treads will be around for at least 50 years. And just to prove it, you're all invited to look with me 50 years from today. I'll post the address of that house when that time comes and will supply brats and beer for everyone of you who shows. :-)
Knowledge is power, but only if applied in a timely fashion.