REsiding. Can I apply new tyvek over old tyvek?
MackB61
| Posted in Construction Techniques on
I am residing my 23 year old house located in central Mass.. House has 4″ cedar clapboards that were installed unfortunately smooth side out with 6d galv box nails. House sits in middle of a field, constant sun. Also very early American with 10/12 pitch and minimal soffets.
Will be installing clear vertical grain cedar at 3.5 to the weather-pre primed. Question is should we remove the old Tyvek or is there any advantage to installing new Tyvek over old?
Appreciate any thoughts
Bob
Replies
I would apply felt over the tyvek because it is a known problem that cedar can break down tyvek.
I'd be interested to know whether he had any such problem with the old Tyvek.
There is some reason he wants to replace/cover it. My guess is that it is just full of nail holes, but it could have some tannin damage.
Like I said, I'd like to know if there is evidence of "tannin damage". The number of credible reports of that is vanishingly small.
Follow the felt recommendation.
re: 23 year old house -- that is awfully young to need new siding, even in the sun. Why?
Make sure you do not use the same type paint again!
I agree-in particular as I think it has been stained at least 3 times if not 4. Last time the wife talked me into having a contractor do it-worst job ever.
I think no. one problem is it was not back primed initially. Mistake no 2, I let the builder BS me into smooth side out. Mistake no .3, builder used like 6d box nails. galv but no holding power.
Could I have salvaged it? Perhaps but what would I have- another crap shoot with a lot of marginal cedar that was cupped, split etc. My plan is to put a second coat of oil based primer over the factory prime and then a finish coat of Ben Moore Arborcoat (solid)
My first thought is a question: What's wrong with smooth side out?
Second thought is a suggestion: Consider using a rainscreen type of installation. http://www.greenbuildingadvisor.com/ has a lot of information.
Third: I agree that reusing the old housewrap is false economy. (So is not using a rainscreen, in my opinion, but I live in a very wet area that sports wind-driven/horizontal rain.)
Hey, if you read the installation manual for tyvek, they recommend a cedar breather product to keep the claps drier (and possibly out of contact with tyvek) . It's a good idea anyway. Apparently there was a change in tyvek at one time and they changed the name from house wrap to home wrap or vice versa, so if yours is the current version you should be OK. I just never bought into the idea of that stuff, and still use felt. Back priming cedar is a very good idea too.
You might want to consider using Tyvek "DrainWrap" vs standard Tyvek. It's a better choice with wood claps where wind-driven rain can get through fairly readily.
Felt over the Tyvek is unnecessary.
Rainscreen
Hi Bob,
I'm not sure if you've started the re-siding project yet, but I'd like to throw in a gentle nudge for you to really consider a rainscreen approach. Creating a ventilated airspace behind your siding will alleviate the problems with premature failure. You wouldn't have to bother with a second coat of oil primer, which may or may not help anyway, because the ventilated space will eliminate the ability for pressure differences and moisture to "push" the paint/stain off the wood. In your case (with clapboards), the job is pretty simple.
To be blunt, I wouldn't consider doing a siding job (unless I was patching and trying to match the plane of existing siding) without a rainscreen approach.
Now, my unofficialy and objective opinion of Tyvek's Drainwrap is that I don't like it. it's essentially crinkled housewrap, which makes it hard to install nice and smooth (staple, pull, and it just stretches). There's a Benjamin Obdyke product called HydroGap which looks nice, but I've not tried it yet. They also make Homeslicker, which I think is far too expensive to be justified except maybe under sidewall shingles, and even then I think there are better methods. Another is Raindrop by Pactiv, which I believe is a woven housewrap...not as high performance as a nonwoven polyolefin wrap (such as Tyvek, Typar, etc). There are others in this rainscreen wrap category...it's a growing market.
For me, I like 1x3s, or even masons lath (which I've not tried, but learned about from Andy Engel).
bottom line: it's worth the extra bucks and effort. There are lots of Fine Homebuilding articles with details. Greenbuildingadvisor.com, too.
[Edit to answer your actual question... I would definitely apply housewrap over the old stuff, which can be left in place. A rainscreen approach eliminates any worry of tannin problems, which are, as mentioned, somewhat controversial]
Good luck,
Justin