joseph moore
09-20-2014, 1:00 PM
Hi. I recently posted about the back wall of my house which I more or less totally rebuilt and added sheathing to. Previously there was none. My concern in my other post had to do with flashing the windows since the ones I am using are re-purposed old windows and have no nailing fins/flanges.There were many great responses to that and I am a lot clearer on that aspect of things now.
I had been toying with the idea of doing a rain screen on the back wall. I will be using pine novelty siding. (7 1/4 by 3/4) My reasons for wanting the rain screen are as follows-
1) the siding on the back of the house is very close to the ground and I read an article that said rain screens were really good for this type of situation where moisture could wick up from the ground.
2) even though I am in Upstate NY which may not be a notoriously rainy area, the Yearly averages that I looked up are saying something in the neighborhood of 40-44 inches per year which seemed significant. Am I reading these figures wrong? Does that include snowfall? I tried to search for exclusively rain fall figures.
3) the main reason I had to rebuild the wall was due to rot from Moisture and Termites which obviously go hand in hand. We are putting a new roof on this fall which will feature a 12" overhang over this wall where previously there was only a 3 inch overhang. That will obviously help a lot too.
I've read just about everything I can find in the limited time I have to research this regarding rain screens. Here's what I know and also what I'm thinking I'd do. Please advise. I'm sure I'm wrong about some of it.
1) vertical strips of plywood attached over the Tyvek which I installed a few days ago. This does not need to be Pressure Treated because the design is such that the strips will dry out. Covering the strips with strips of building paper might be a good thing. Does that mean they should be just covered on the face with the edges of the ply still uncovered?
2) Insect screen applied a few inches from the bottom of the sheathing then wrapped up over the face of the plywood strips, creating an insect barrier. This should probably be metal not Fiberglass, correct?
Aluminum ok or should it be galvanized?
3) All aspects of siding and trim would be installed on this new plane created by plywood strips. This would include corner boards, PVC water table (or skirt board), and window and door casings.
4) I imagine the strips under the corner boards would be simple enough. they would just need to be big enough to nail the corner board to as well as the end of the siding that is butting in. So in the case of a 3 1/2 inch wide corner board there could be two ways of doing it- install a plywood strip that is 4 1/2 " that goes all the way to the edge of the corner and exceeds the width of the corner board by 1 " creating a nailer for the siding. Or- rip a smaller strip maybe 3" and just start it 2" in from the edge of the corner so that 1 1/2" inches is under the corner board and 1 1/2 is under the siding. I think this might be good seeing as the corner boards will be pre- assembled on the ground so they will be plenty strong even if they are unsupported for the 2" closest to the edge. This would also allow for drainage behind the corner board.
5) The PVC water table will be attached directly to the strips. There is an integrated drip cap on the product I'm using btw. The question here ( and with the head casings on the window/doors) is usually I would leave the house wrap long, lap it over the water table drip cap and trim it after the siding went on above it. I won't be able to do that here. Same with a metal flashing piece. even though it's pvc I believe it's still recommended to use a metal flashing to keep water from going behind the drip cap. Maybe that isn't necessary if the water can drain.
6) Windows and Doors. This is where most people's confusion is....mine too. I have found a lot of new construction detail directions but I'm unclear about my situation. So what do I do here?
Same deal on the side casings as the corner boards....is it one wide strip supporting the entire casing and the end of the siding that butts in? Or is it multiple strips creating a drainage channel? Either way, what happens with the self adhering membrane I plan on using? Is it over the strips? Under? Both?
7) Head casings.....completely confusing. Are these vertical strips again and if so what happens with the house wrap that one would usually be using to overlap the drip cap after he had applied a head flashing?
By the way I am planning on using 1/4 CDX plywood for the strips. I'll use 3/8 if the lumber yard doesn't have 1/4 CDX. But nothing larger than that. Also this is only for the back wall of the house only. The adjacent walls are keeping their original 150 year old siding. Thanks in advance for any help sorting this out.
I had been toying with the idea of doing a rain screen on the back wall. I will be using pine novelty siding. (7 1/4 by 3/4) My reasons for wanting the rain screen are as follows-
1) the siding on the back of the house is very close to the ground and I read an article that said rain screens were really good for this type of situation where moisture could wick up from the ground.
2) even though I am in Upstate NY which may not be a notoriously rainy area, the Yearly averages that I looked up are saying something in the neighborhood of 40-44 inches per year which seemed significant. Am I reading these figures wrong? Does that include snowfall? I tried to search for exclusively rain fall figures.
3) the main reason I had to rebuild the wall was due to rot from Moisture and Termites which obviously go hand in hand. We are putting a new roof on this fall which will feature a 12" overhang over this wall where previously there was only a 3 inch overhang. That will obviously help a lot too.
I've read just about everything I can find in the limited time I have to research this regarding rain screens. Here's what I know and also what I'm thinking I'd do. Please advise. I'm sure I'm wrong about some of it.
1) vertical strips of plywood attached over the Tyvek which I installed a few days ago. This does not need to be Pressure Treated because the design is such that the strips will dry out. Covering the strips with strips of building paper might be a good thing. Does that mean they should be just covered on the face with the edges of the ply still uncovered?
2) Insect screen applied a few inches from the bottom of the sheathing then wrapped up over the face of the plywood strips, creating an insect barrier. This should probably be metal not Fiberglass, correct?
Aluminum ok or should it be galvanized?
3) All aspects of siding and trim would be installed on this new plane created by plywood strips. This would include corner boards, PVC water table (or skirt board), and window and door casings.
4) I imagine the strips under the corner boards would be simple enough. they would just need to be big enough to nail the corner board to as well as the end of the siding that is butting in. So in the case of a 3 1/2 inch wide corner board there could be two ways of doing it- install a plywood strip that is 4 1/2 " that goes all the way to the edge of the corner and exceeds the width of the corner board by 1 " creating a nailer for the siding. Or- rip a smaller strip maybe 3" and just start it 2" in from the edge of the corner so that 1 1/2" inches is under the corner board and 1 1/2 is under the siding. I think this might be good seeing as the corner boards will be pre- assembled on the ground so they will be plenty strong even if they are unsupported for the 2" closest to the edge. This would also allow for drainage behind the corner board.
5) The PVC water table will be attached directly to the strips. There is an integrated drip cap on the product I'm using btw. The question here ( and with the head casings on the window/doors) is usually I would leave the house wrap long, lap it over the water table drip cap and trim it after the siding went on above it. I won't be able to do that here. Same with a metal flashing piece. even though it's pvc I believe it's still recommended to use a metal flashing to keep water from going behind the drip cap. Maybe that isn't necessary if the water can drain.
6) Windows and Doors. This is where most people's confusion is....mine too. I have found a lot of new construction detail directions but I'm unclear about my situation. So what do I do here?
Same deal on the side casings as the corner boards....is it one wide strip supporting the entire casing and the end of the siding that butts in? Or is it multiple strips creating a drainage channel? Either way, what happens with the self adhering membrane I plan on using? Is it over the strips? Under? Both?
7) Head casings.....completely confusing. Are these vertical strips again and if so what happens with the house wrap that one would usually be using to overlap the drip cap after he had applied a head flashing?
By the way I am planning on using 1/4 CDX plywood for the strips. I'll use 3/8 if the lumber yard doesn't have 1/4 CDX. But nothing larger than that. Also this is only for the back wall of the house only. The adjacent walls are keeping their original 150 year old siding. Thanks in advance for any help sorting this out.