Insulating cottage with cedar siding and tentest wallboard.
7/10/2023 at 2:32:36 PM
Our question what is the best way to insulate the walls of a three season cottage that currently has cedar siding over tentest boards attached to 2x4 studs. We have already completely gutted the inside back to the studs. The tentest is in okay shape but has holes in some spots. The cedar siding has multiple spots that are cracked or missing boards. So specific questions are 1. Can we just add insulation and a vapor barrier on the inside walls and fix the cedar siding in spots or 2) Should we remove the siding, add house wrap and put up new siding and if we do so do you need to add strapping for the siding or can you put siding right on the tentest? And if we need to do strapping, any tips to avoid it becoming a mouse hotel.
7/12/2023 at 7:34:27 PM
The right way is to re-do it. Take off siding and start from scratch. You will then have a structure that will last, meet codes and be resaleable
7/12/2023 at 7:50:28 PM
Thanks John, I don't believe it will ever meet code with 2x4 walls, but I am concluding from your answer that the Tentest is crappy and needs to be replaced.
7/13/2023 at 4:24:34 AM
From what I have seen about the tentest after a brief Google search is that it has been proven to be durable after a 30 year trial and that it is a good product provided it is not off-gassing or been compromised by rodents. If there are a lot of holes these will have to be properly repaired.
To answer your question there should be no need to strap overtop of it as this will only give you more problems not only with possible rodents or insects but also creates more work in detailing around door and window openings. If you are located in a region of very high rainfall (i.e. the lower mainland) strapping beneath various types of claddings becomes more important as well as required to meet Code in those environments. I did see Mike Holmes strap a home beneath siding so it is done and is not a bad idea in general. Creates a 'pressure-equalized rainscreen'.
7/13/2023 at 12:05:34 PM
Thanks Ian, any tips on fixing where there are holes in the Tentest?
7/14/2023 at 3:38:17 PM
I don't have any specific recommendations. Best bet is probably to take some photos and visit your local hardware store and/or check with a pest specialist to make sure any repairs are rodent resistant.
7/18/2023 at 4:26:04 PM
Ian is a dear a friend and while the holes "might" be fixed, your exterior structure is damaged & used what is now considered substandard methods. As the guy who actually fixes these things I can assure you with all the issues combined, the only right way to do it is take all apart and re-do with modern materials otherwise you are doing a half job and it will come back to haunt you. There is the professional way and the wrong way on all construction. Good luck
PS: most houses prior to 1980 were 2x4 walls and they are grandfathered so you are ok, doing new construction you must use 2x6
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