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>There are some building practices that I have always followed because I was taught that this was the proper way to build a “quality” house. However, I have recently questioned the usefulness of a couple of those practices. Please tell me if I’m missing something here.
>#1) The use of treated mudsills. I understand why one would use treated wood anywhere that wood comes in contact with dirt or concrete. With a mudsill though, we first install sill seal (we use a closed cell foam that is ~ 1/4″ thick X 6″ wide and comes in a roll). I know that the primary purpose of the sill seal is to stop air infiltration but it also prevents the mud sill from coming in contact with the concrete foundation wall. On the outside of the wall, we let our 7/16″ OSB sheathing hang below the bottom of the mudsill about 3/4″. Then our siding drops below our sheathing another 3/4″. So the mudsill seems to be pretty well protected from any moisture migration. With this in mind, do you really think it’s necessary to use treated lumber for the mudsill?
>2) Dampproofing the exterior of a crawlspace foundation wall. It seems to me that rolling or spraying on a coat of asphalt based foundation sealer is a waste of time and money. The stuff available around here comes in a five gallon bucket and looks like runny tar. You paint or roll it on or hire a guy with a heated tank to come spray it on. It does not cover all that well. All the little voids in the concrete want to cause bubbles that pop and leave unprotected little pockets everywhere. While these pockets are small, they are still there. I have tried being very particular, cleaning the concrete wall and the footing very carefully and taking a long, long time to ensure that all the voids get filled but I still don’t know that I covered 100% of the concrete surface. If I was truly concerned about stopping moisture, I think I would use the expensive polymer-based sealers or even the sheets of sealer you stick to the wall and protect carefully during backfill. Anything short of that seems to be an exersize in futility. I don’t want to spend the time and money (not to mention the mess) if it’s ineffective.
>There are others that I will mention in a later post. Thanks.
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Those are good questions Ray. Do you guys then vent your crawlspaces? If the concrete is gonna absorb moisture from the ground, won't it absorb it through the bottom of the footing too?
For the cost of the mudsill, I still use them without reservation. I have seen way too many fir sills rot after 60, 80, 100 years, and I hope my buildings will last longer than that.
The technique I most often question is breaking your top plates over a stud. Look what you do to the end of the plates, not to mention shredding the top of the stud with 4 16d nails.
*If my top plates break over a stud it is by coincidence. I don't break the double within' 2' of the top break, and I sheath with osb or plywood always, so in my opinion it doesn't really matter. It has never failed an inspection.
*Ray,I've had that same thought about damp-proofing the crawlspace walls. It does seem a bit unnecessary if the outside grade is appropriate. But it's a moot point in areas subject to CABO building codes. Damp-proofing is required.Chase
*Leave out the second or third kitchen before you leave out the capillary break and the rot resistence...near the stream,aj