I’m not so sure if finding this site is a good thing. Too many things to keep me up at night. Anyway I recently found the threads concerning cedar being placed over Tyvek. Last year we had a small (only 180 sq. ft.) addition put on along with a kitchen remodel. It was for a mudroom and 3/4 bath. The contractor (who I thought was very thorough with his details) put on Tyvek and covered it with Cedar shingles. Reading the Archives this seems like a “bad” thing. The Cedar was not back primed nor placed on firing strips though it has been stained with a clear stain on the exterior now. I, and apparently he, didn’t know any better.
So what do I do now? Do I call him back and tell him I’m worried about this? Obviously he’s already been paid but is this going to cause problems (with the house not the contractor)? Should he fix it?
The house is only partially painted because we’d like to do the entire house in Clear cedar eventually. The rest of the house has a serious paint issue as do all of them in the neighborhood. Old neighborhood, just North of Boston built 1935. Lot of big old trees that slow drying after it rains. Planning on staying here for a Loooooooooong time.
I plan to reshingle the rest of the house on my own (only way we’ll ever be able to afford it) Back coating shingles just seems like and absolutely incredible amount of work to archive this type of finish. I guess based on the threads I could just use 15# or 30# Felt for the rest of the house. The old house now has individual planks (not plywood) covering the studs. Interior is plaster (very good condition) over lathe. I was also going to dense pack cellulose in the walls which presently have no insulation. Obviously based on the paint issue there is also some type of vapor issue.
Gets more complicated every day. I’m not afraid of the work I just want to do it right.
Replies
In my opinion the whole thing's overblown. The cedar against Tyvek problem seems to be mostly theoretical, and in any case won't result in spontaneous combustion or some such, just less than ideal wind/water protection. (And if water is getting through the shingles then they weren't very well installed.)
It's not theoretical at all. I've seen the results - Housewrap that had the strength and water repellency of tissue paper, leading to the beginning of rot.
That said, would I tear off the shingles? Probably not, but I'd keep a close eye on that section of wall. There's a lot at play. How exposed is that wall? If it's the northeast side, in New England, I might look closer. The tannins work fastest if transported by water. Here, the northeast sides of houses get blasted by winter storms and summer hurricanes. I'd also be concerned about the west side. Soak the wall with a summer thunderstorm, after which the sun comes out, and there's a huge moisture drive inward. (Moisture always moves from wet to dry and from warm to cold. The sun's heat pushes it inward, toward that nice, cool air conditioned side. And since we're talking vapor here, it'll pass through the housewrap, condense inside the wall, and then you've got a situation.) The problem doesn't happen overnight, though. I've heard of bad trouble occuring in 5 to 7 years. The case I fixed last summer was about 20 years old.
Andy Engel
Senior editor, Fine Woodworking magazine
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
Edited 4/15/2005 10:23 pm ET by ANDYENGEL
Edited 4/15/2005 10:23 pm ET by ANDYENGEL
The issue is that the tyvek will not perform well as a secondary water barrier after reacting with the cedar. Worst case, you get wet walls, rot/mold/mildew. Without back-priming, the clapboards will not dry evenly, and may warp/twist/pop. Moisture soaked through the back will push the paint off faster than otherwise. Actual results depend a lot upon the weather exposure, overhangs, gutters, and other factors. Though not best-practice, I would not go and take it off unless the flashing was done poorly.
"Back coating shingles just seems like and absolutely incredible amount of work to archive this type of finish."
You can get pre-primed.
"I guess based on the threads I could just use 15# or 30# Felt for the rest of the house. The old house now has individual planks (not plywood) covering the studs."
Felt is a better material in many ways. Ideally, you would use a rainscreen design anyways. Search for recent "Rain Screen" article in FHB.
"Interior is plaster (very good condition) over lathe. I was also going to dense pack cellulose in the walls which presently have no insulation. Obviously based on the paint issue there is also some type of vapor issue."
Air control techniques, followed by densepack is a good formula in the Northeast. If it balloon framed, you will want to add solid blocking at the sills and rimjoists to control air movement (and fire).
Edited 4/15/2005 3:54 pm ET by csnow
I've seen preprimed cedar siding for painting but never for individual shingles?I guess they're out there I just haven't seen them.
"I guess they're out there I just haven't seen them."
They are out there. I even saw some at a big box store recently.
Ribs, probably 98% of the houses out there built or remodeled in the last thirty years have Tyvek or a similar housewrap. Yes, there is supposedly an interaction between the extractives in cedar and the resin in Tyvek, but I wouldn't go tearing off any shingles because of it.
At a real lumberyard you can get pre-stained shingles, either one or two coats. Don't know about painted, but even a clear sealer will prolong the life of your paint job. Maibec is the biggest name in New England, but Frasier makes a comparable product for less money.
Mike
Years back I sided a school with 1 x 6 cedar lap siding. I purchased 10 rolls of tyvek and sent the invoice in for the free fishing rod and reel, a promotion that Tyvek had a that time. Anyway, 16 years later no problem, I would not worry about it.
You saying the rod and reel are still good?;-)
Ive done a few jobs where not putting Cedar against tyvek was req'd and so am led to beleive that it can cause problems (Maybe somewthing we will never see in our lifetimes though ;-) ). Never been advised not to put up Cedar shingles over Tyvek though, just with sills / trim etc...
To avoid this with sills and trim. we would put a strip of Vycor / ice & water between the cedar and tyvek.
Carpenter / Builder, Rhode Island
Never used it, nice rod and reel set, still in the package, arrived via courier on Christmas Day. 10 rolls of tyvek at about $200.00 a roll back then, it only cost me $1000.00....I better get it out and use it.
Maybe move to Fiber cement planks
Ribs,
This article may be of interest to you.
http://www.umass.edu/bmatwt/publications/articles/housewraps_feltpaper_weather_penetration_barriers.html
For what it's worth, I have done it both ways in the past and have not seen any adverse reactions yet, maybe time will tell. I just did my house and used Tyvek, mainly because it had to ride out the fall unsided and the felt would have buckled all up. I did back prime and let the cut ends drink up lot's of sealer.