any ideas on best products / techniques/ or the need to upgrade the exterior surface of an existing green-wood foundation wall? the original construction of this 30 year old house has tar paper stapled to the exterior plywood of the foundation wall. there is some sort of black stuff painted to the plywood underneath the paper, but it doesn’t look like it has any waterproofing qualities at all. the tar paper above grade is pretty much gone and the plywood is showing some weathering. there is no moisture evident in the crawl space (good drainage in a rocky soil).
i am unsure what to recommend. is a resurfacing down to the footing necessary? i’m concerned that anything done only part way down can invite moisture to be trapped underneath the new surfacing. maybe that is of no concern with green-wood? being green-wood, is there any need to do anything at all? any work is best done now before decks and additions get added to the structure.
jim
Replies
I use Bituthane on the wood foundations that I have done. It comes in a roll that is 3' x 100'. I start at the bottom of the footer and go up from there, that way there is no way that any water can get in.
If it's a warm day it should stick real good but if it's on the weather is a little bit cooler then I would use the primer. Be advised that once you stick it to the wall there is no adjusting it, espesially when you use the primer. Also don't allow it to fold up on itself or get stuck together in any way otherwise you'll never get it apart. You'll just have to cut that part out and throw it away.
The slang term for it is Bitchuthane, and it's called that for the reason that I just mentioned.
Good luck, Dave
thanks dave,
i'm familiar with the stuff. so it sounds like you would recommend digging down to the footer and doing the entire wall? jim
I could not advise on a wood foundation wall to any extent, but here in Mississippi we contend with several problems concerning foundation waterproofing. As an architect, we have to not only deal with ground water hitting foundation walls, but also the fact that water will percolate to our indigenous soil called yazoo clay and causing it to shrink and swell thus making slabs and foundations rock and roll. There for with extensive knowlege on this subject and not much else, I will tell you what we use here for what I think are some of the most severe cases of foundation water control methods. First there is a product generically called hydrocide. It is made by the Henry Corporation. It is a black thick tar-like coating which can be applied with a roller. I believe it could be used on a wood foundation. The coating should be about 1/16" thick when finished. The second system was mentioned by others posting on this subject, and that is bituthane. It is available in a membrane type of material that is adheared to the foundation wall. It is about 1/8" thick and some typical manufacturers are W.A. Grace. Some other products you can use to divert water away from a foundation wall is a product called Mira-Drain or Poly-Drain. This is a drainage mat made of ABS plastic with hundreds of dimples. This can be used over the bituthane. It has a filter fabric on the dirt side of the foundation wall. When water migrates toward the foundation wall it goes throught the filter fabric and hits the dimpled portion of the drainage mat and flows downward to a french drain system or tile. I've probably told you way more than you want to know. I'd check with a company like W. A. Grace or similar manufacturer of below grade bituthane and verify the compatability with wood foundations. It is great stuff. Good Luck Eric
thanks eric,
all good information...thanks for the time. jim