Tyvek vs foamboard, for back of frame.

Create a Post
K

Ken R.

CGF, Certified Grumble Framer
Joined
Apr 9, 2011
Posts
115
Loc
Western Michigan
I know this has be visited many times, but not recently, that I could find. Instead of using several layers to foamboard to fill the back of a deeper frame, how about just one layer of tyvek on the back?? Tyvek per square inch is about the same price as foamboard, and I still need backing paper anyway, so I wonder......Is tyvek strong enough and puncture proof enough that it will hold over a void of perhaps 3/4" deep. i would use Gluefast's Mathesive to fasten it to the frame back....


What do you think?? Inquiring minds want to know.
 
Hmmm… Tyvek alone would certainly be a lot stronger than paper applied in a similar manner, so you’re ahead of the game there. But another reason to fill out the back is to fill in that big void of air. Doing that will provide a good deal of mass that will provide a nice microclimate and slow down swings in temperature and humidity.

You could always compromise by lining the side of the frame with some strips of board and then use a single extra layer of material. Similar support to the dust cover with far less material used. As usual it comes down to how much preservation you want.
 
Also, filling the frame makes the entire package more solid. While with a beefy enough frame this may not be an issue but if you are using a cap moulding that has a large void on the back, hanging from a wire can cause additional stress on the corners. The wire is pulling the back of the frame inward and can cause warping of the frame. Filling the frame with a board will provide a stop for frame and thus make for a stronger package.
 
Lets get gutter-tramp street level Ken.....

You know all of those stupid pieces of 5"x32" foamcore you have been saving?
this is when you get rid of them. Layer one run vertical, one horizontal..... you
don't have to be exacting if you made the first layer of the sandwich in some
roached/dinged/oops rag board then the scrap and scab.... and finish with
a cleaner looking whole sheet of what ever. Little dots of glue to hold every
thing together or a little ATG. Either way it is a cohesive backer.... that like
Dave says.... regulates the temp and therefore the humidity.
 
I use it on deep frames. I have not found layers upon layers of foam core to make anything strong or to prevent warping and torquing of the frame.
 
laying layer upon layer is only as strong as an individual board.....

but weld/glue those layers together... and it works like ply-wood vs veneer
 
How about one level of foamboard, then adding a strainer for support? Then tape up the back, like the Eurotrash do.
 
Ken, the tyvek would probably be strong enough for protection against puncture but would not provide any support to the side rails of the frame. Many of the old tall thin frames that have a big void in the back are twisted inward from the strain of the wire. By filling the backs in with fome core the frame is less likely to want to turn inward.

If you want to do away with the expense of fome core you could build an inner frame out of strainer board to give the frame rails more support.

I don't like Baer's suggestion of gluing together fome core strips and filling the frame with them. That would look like the old frames I have opened that were stuffed with scraps of cardboard taped together. If for no other reason than appearance, scab framing should not be done :) Just think would you would think of the framer if you opened the framing package....
 
If it is a thin, deep moulding, using a strainer would be preferable to several layers of foamboard. The strainer will provide structural support to the frame, and you can (and should) put the hanging hardware onto the strainer, rather than the frame.
 
Create a Post
Back
Top