Hoping to add fiber cement shake panels on top of t-111 siding. The t-111 is in good shape, don’t like the look. The house is in mountains of western North Carolina. 2×4 walls, fiberglass batts, 1/2” plywood, tyvvec, t-111 siding.
I’m hoping to leave the t-111 up and put shake panels on top.
Should I use felt under the shake panels? Tyvec? Nothing? I don’t want two WRBs conflicting with each other. I feel like I’ve heard something about this.
Thanks for any guidance.
Brad
Replies
Hi, the difference in climate zones may give a slightly modified answer than what I have, but maybe only in the case of changing a major energy deficiency. I don't see any problem leaving the T-111 up, unless there was a fastening issue with the shake panels, but I doubt it.
As for any membranes, I don't see any advantage in the cost of material, even if the labour is free, it's a waste. If you needed to add insulation and/or had doubts about the vapour barrier then and only then might it be suggested. But you don't want to create a double barrier whereby moisture laden air is trapped between even though most are moisture permeable and as you stated already have one in the wall assembly.
You may want to consider a ventilated rainscreen layer since the fiber cement panels are the new siding and need a ventilated space. Maybe Corr A Vent since they have many products to pick from, although they have not paid or given the writer substantial monetary gain from mentioning them. I would do this on any project for a client or myself, in fact I wouldn't do it without it. Cheers Mark w ArtisBuilders