Weather sealing an exterior door
Weekend worrier here (well – retired, so 7-day worrier), working on my own property.
I’m reworking a storage shed, built on slab, into a workshop (my wife’s not mine). It’s finally getting a decent door as part of this.
The brick patio outside the door is minimally lower than the slab, and the door’s on the weather side to make it worse. The jamb for the prehung door I bought rests on the endgrain of the jambs, and I want to make this as durable as possible and minimize water infiltration.
I’m contemplating screwing down 1/2″ treated ply throughout the shop space and into the door opening, sealed with polyurethane at the door opening, which will give me a little height; painting all surfaces and edges of the jamb (of course); and putting self-adhesive flashing on the endgrain and up the back side of the jamb a little.
I will be putting down a floating floor, resting on top of the padding they recommend. If I put down plywood, my plan is to put down plastic under the ply as a vapor barrier and run it up the walls to fasten to the treated mudsill.
I also have to devise a method of sealing the underside of the aluminum threshold to the slab or plywood; the threshold is an extrusion with fins coming down intermittently across its width, and spaces between. I’m considering adhering some treated wood in the space at the outside of the opening and then caulking the daylights out of it (polyurethane again) as I set it in place.
Are there better methods? Is this workable? Do I need to be concerned about treated plywood in an occupied space?
Replies
wow
Several questions.
Here's one answer. Buy the prehung entry door that has what is being called Jamb Saver. This is a composite bottom foot or so of the jamb. They used to also make the alum. extrusion threshold that was over a pc of wood-no longer. This has eliminated at least two main rot out and decompose areas of entry doors.
I would build up the door base area, but first fabricate a "pan" out of a Vycor type of product-they are made for these purposes-Think Window Sealing. Frame the walls and then do your plywood / vapor barrier whatever inside the room. Leave the concrete at the door way.
Take the peel and stick (vycor type product) and go across the opening and up the trimmers on either side. Lip up the product at your plywood buildup (the long side of the door opening. Take it out an down over the edge of the slab. Apply corner patches as necessary to seal all water OUT OF the building. Allow it a way out, off the slab.
Now, to build up the door so it clears with plenty of room to put a throw rug inside, use maybe a pc of composite decking (1" thick). Place that on top of the vycor type product and fasten to the concrete with a couple tapcons after you have leveled it.. The pan you made under it will seal around the tapcons.
Set the door on top of that-apply a bed of caulk towards the outside and inside of the threshold. All the way across with a buildup in the corners.
This should keep water out and protect the interior if there is intrusion. Don't forget to detail the sides and head of the door jamb well.
Best of luck.
A simple roof, even extending less than a foot, will keep lot of water from the door. weather membranes may have the effect of trapping moisture or keeping the endgrain from drying out. I would just treat it and keep it spaced from the pan or the concrete. Hope it helps.
Seal The Jambs
Seal the jambs' endgrain with marine grade epoxy, then add a good urethane sealant and screw your tin sill to the bottom of the jambs and set it in some sealant on your floor. Hopefully you have an outswing sill. You can also make a wood sill out of White Oak and rabbet it to keep out driven rain.
My opinion is that Jambsavers, et al, are all just feel-good things that make you think you are forestalling the inevitable quick decline of a yet another mass produced building product that is made as cheaply as possible. Avoid finger joint and boguswood. Use W Oak, Real Mahogany, Cypress, W R Cedar or white pine.
You can fill the underside of the aluminum sill with urethane glue or sealant and then set the frame. Once it cures, it will be sealed and immovable.
Dave Sochar
http://www.acornwoodworks.com