Hi all! Just realized that the home we bought almost six years ago (built 1977) doesn't have plywood on the exterior under the siding. Looks like it's just framed and then a 1" insulation board was installed on the outside and then the siding. It's freaking me out a little that there's no plywood. Should I be worried?
No, this was a common practice for a while and is making a comeback. This was done to increase R value, if it was done correctly the corners are plywood/OSB and there should be steel diagonal "T" bracing in certain areas. Yes if you are use to normal frame construction it is a little surprising when you first see it. My thoughts always were, vinyl siding, styrofoam then drywall, I can almost walk thru that wall. The vinyl is the toughest part.
As long as it's dry the house was won't "fall down". But you might want to look into some form of after isolation and other measures to get the house more airtight?
The other thing is if you go to replace windows or doors the jambs are usually thicker because the foam is 1 inch and OSB would be 1/2 inch.
This is true.. my thought was... what security is it to lock door? when a knife can cut right thru.. Chris... just look to see where metal braces are and make sure they did not cut them for Windows and doors!
It's definitely dry... too dry. My basement where the wood stove is gets down into the teens (RH). Rest of the house is 30% at best. I had my whole house humidifier running for two days straight and I think I gained 1%. Most likely because I need new windows on the first floor.
they use 1 inch foam board instead of half inch plywood.. 1 inch board has r value of about 5 .. plywood .33? in 5 star construction it's is glued to 2 by 4 which are 24 inches on center instead of 16.. also thicker so a 2 by 4 studs with foam and drywall are same width as a standard 2 by 6 wall.. so normal depth windows and doors fit.. Viking80 does our stud sizes make sense to you a 2 by 4 would be rough cut then planed so it actually is only 1.5 inches by 3.5 inches by length of feet... about 2.2 cm per inch
RH in winter is going to be fairly low, unless you add moisture....which you've tried. A lot of us have pots of water or some other water vessel on the wood stove all winter to help. The RH in here is 30% right now, and it sometimes drops down into the high 20s, even with the water on the stove.
Hey, thanks for asking! Firstly thanks for clarifying the thicker foam board vs. the thinner plywood. Here's an illustration of how it's often done here: And yes; it's still called a 2x4 here too, even if it's not a literal 2x4 anymore. However the proper measurements for a "2x4" here in Norway is 48mm x 96 mm (planed).
Mine had NOTHING between the siding and the insulation! No OSB, plywood, foam, or even Tyvek. So it went - siding, insulation (unfaced), drywall. This kind of siding: Do you think it might have leaked a little air?
ICF wall hurricane test 100mph I think They also shoot thru conventional 2x4 stud walls with plywood and/or green wall sheathing . Right thru. at 75 mph. No sheathing can't be very much protection from much of anything. Maybe in a tornado it is better that the sheathing blows away leaving bare studs.
