# wall sheathing question



## markharmon (Apr 24, 2013)

Hi guys,

I have some quick questions. When you have your 8" thick foundation wall should you install your sill plate recessed in a bit to account for sheathing and an space for the sheathing to rest on? Or should the sill plate be flush with the outside of the foundation wall? Same with rigid foam do you set the sill back to account for the rigid foam as well?


----------



## GBrackins (Apr 26, 2012)

sill plate should be about a 1/4" past the outside edge of the foundation. you do not want your wood sheathing against the concrete as it may wick water. at least that's how it's done in my area


----------



## woodworkbykirk (Sep 25, 2011)

gb is right, the reason is to create a drip edge of sorts. .when water runs down the wall it runs down past the joint between the plate and the foundation so it bypasses that joint and doesnt run into the house


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> sill plate should be about a 1/4" past the outside edge of the foundation. you do not want your wood sheathing against the concrete as it may wick water. at least that's how it's done in my area


1/4" past or in from the outside edge? What about if you have rigid foam? Does that start from the sill and go up and just overhang at the bottom?


----------



## MJ Force (Jan 1, 2013)

Generally you place the sole plate flush with the edge. In most cases there will be a channel or rabbet where the leveling strip for the foundation wall was placed. Your sole plate sits at the edge of the rabbet and on top of a sil gasket of course. Your subsequent layers of sheathing and siding will step the building envelope away from the concrete wall. Do not let the sheathing touch the concrete. It only covers the sole plate. Your final siding should be stepped slightly lower than the previous layer. A 1/4" to 1" lower for each layer depending on the materials and method used. 

If your really worried about it or if you get heavy rains, place a small drip flashing between the siding and the previous layer to kick out any water running down.


----------



## GBrackins (Apr 26, 2012)

the sill plate (which is attached to the top of the foundation with anchor bolts) overhangs the exterior side of the foundation 1/4". you do not want your wood sheathing in contact with the foundation


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> the sill plate (which is attached to the top of the foundation with anchor bolts) overhangs the exterior side of the foundation 1/4". you do not want your wood sheathing in contact with the foundation


MJ says keep it flush and you say to overhang it 1/4"?


----------



## markharmon (Apr 24, 2013)

MJ Force said:


> Generally you place the sole plate flush with the edge. In most cases there will be a channel or rabbet where the leveling strip for the foundation wall was placed. Your sole plate sits at the edge of the rabbet and on top of a sil gasket of course. Your subsequent layers of sheathing and siding will step the building envelope away from the concrete wall. Do not let the sheathing touch the concrete. It only covers the sole plate. Your final siding should be stepped slightly lower than the previous layer. A 1/4" to 1" lower for each layer depending on the materials and method used.
> 
> If your really worried about it or if you get heavy rains, place a small drip flashing between the siding and the previous layer to kick out any water running down.


How come GB is saying to extend it over 1/4" What do you mean by will step the building envelope? I guess my whole thing is when you leave the sill plate flush with the edge of the foundation wall and and sheathing, wrap, rigid foam and siding and you look up from under all of this what covers it all? Its not going to down to below grade or anything where you back fill it obviously.


----------



## jsbuilders (Apr 13, 2013)

What kind of siding are you using?


----------



## GBrackins (Apr 26, 2012)

I'm saying this is how it is done in my area. we overhang the sill plate a 1/4" so that the wood sheathing is not in direct contact with the concrete at grade level, the sheathing can wick water which will lead to rot in time (unless you use preservative treated wood, so why have that expense?). overhanging the sill plate leaves a void between the face of the foundation and the back of the sheathing, make sense?


----------



## markharmon (Apr 24, 2013)

jsbuilders said:


> What kind of siding are you using?


For example vinyl but what if I choose fiber cement or even brick. I mean if your overhang the sill plate past the foundation wall there is going to be a gap underneath am I right? What is going to cover that?


----------



## jsbuilders (Apr 13, 2013)

markharmon said:


> For example vinyl but what if I choose fiber cement or even brick. I mean if your overhang the sill plate past the foundation wall there is going to be a gap underneath am I right? What is going to cover that?


Of your really worried about it bend some PVC coated aluminum coil stock (color matched to your siding).


----------



## jsbuilders (Apr 13, 2013)

jsbuilders said:


> If you're really worried about it bend some PVC coated aluminum coil stock (color matched to your siding).



Sorry I'm on my phone


----------



## MJ Force (Jan 1, 2013)

GBrackins said:


> the sill plate (which is attached to the top of the foundation with anchor bolts) overhangs the exterior side of the foundation 1/4". you do not want your wood sheathing in contact with the foundation


This way is correct also. 

In my area the bottom plate is flush with the concrete. I just looked at the plate on my home and its done this way also. 25 yrs ago. Ive always done it like this. Each builder may make allowances for the type of siding used. The important thing is that the sheathing does not come in contact with the concrete.


----------



## markharmon (Apr 24, 2013)

MJ Force said:


> This way is correct also.
> 
> In my area the bottom plate is flush with the concrete. I just looked at the plate on my home and its done this way also. 25 yrs ago. Ive always done it like this. Each builder may make allowances for the type of siding used. The important thing is that the sheathing does not come in contact with the concrete.


so you bring t sheathing down so its level and flush with the bottom outside edge of the sill? What about siding and if you want rigid foam on the outside? Does that come down to the same level as the sheathing?


----------



## GBrackins (Apr 26, 2012)

no, typically the sheathing come down about an inch below your sill plate so that it covers the plate-to-foundation connection. don't forget your sill sealer under your sill plate.


----------



## kwikfishron (Mar 11, 2010)

GBrackins said:


> no, typically the sheathing come down about an inch below your sill plate so that it covers the plate-to-foundation connection. don't forget your sill sealer under your sill plate.


In a perfect World... this is assuming the conc boys got it right. 

Trusses are coming...I'm more concerned with other things working out than I am about that little detail.


----------



## VINNYHARMON (May 6, 2013)

:no: :no: :no:


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> no, typically the sheathing come down about an inch below your sill plate so that it covers the plate-to-foundation connection. don't forget your sill sealer under your sill plate.


What cover the underside? Lets say you have your sheathing, house wrap and rigid foam all about an inch below the sill. There would be a gap.


----------



## GBrackins (Apr 26, 2012)

there is a gap between the foundation and backside of the sheathing ....


----------



## GBrackins (Apr 26, 2012)

you could use a piece of wood the same thickness as your rigid insulation across the bottom that would be attached through the sheathing into the sill plate. this would close the bottom of the rigid insulation. this could be made from sheathing or 1x material. attach your rigid insulation and then your siding.


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> you could use a piece of wood the same thickness as your rigid insulation across the bottom that would be attached through the sheathing into the sill plate. this would close the bottom of the rigid insulation. this could be made from sheathing or 1x material. attach your rigid insulation and then your siding.


Ok but what finishes off the underside exactly?


----------



## GBrackins (Apr 26, 2012)

what do you want to finish it with? it's the bottom of the sheathing, wood to keep rigid insulation unexposed to insects and then your siding.


----------



## GBrackins (Apr 26, 2012)

markharmon said:


> I mean if your overhang the sill plate past the foundation wall there is going to be a gap underneath am I right? What is going to cover that?


what gap are you talking about?

you'd see 1/4" of the bottom of your wood sill plate, the bottom edge of your sheathing and the bottom edge of your finish. there is no gap.

if you use brick you won't see the bottom of anything as you need a brick shelf on your foundation. 

I believe you're trying to over think things .....


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> what gap are you talking about?
> 
> you'd see 1/4" of the bottom of your wood sill plate, the bottom edge of your sheathing and the bottom edge of your finish. there is no gap.
> 
> ...


Hi,

If I have end gables with no overhang or room for soffit how would I install the fascia board?


----------



## GBrackins (Apr 26, 2012)

your facia or rake board goes over the siding "flush" to the wall

see photo 41a http://www.bing.com/images/search?q...5CDE9A08FD849DCB5CC1DD71A8C0E&selectedIndex=1


----------



## markharmon (Apr 24, 2013)

GBrackins said:


> your facia or rake board goes over the siding "flush" to the wall
> 
> see photo 41a http://www.bing.com/images/search?q...5CDE9A08FD849DCB5CC1DD71A8C0E&selectedIndex=1


Can you buy flush fascia rake boards because the fascia I have seen have that 3/4" lip at the bottom?


----------



## jagans (Oct 21, 2012)

markharmon said:


> For example vinyl but what if I choose fiber cement or even brick. I mean if your overhang the sill plate past the foundation wall there is going to be a gap underneath am I right? What is going to cover that?


Who cares about the gap? Bugs need a place to live too. Gary told you the reason for the gap. Its so wicking does not occur. A drip edge is formed, so water dosent travel to the sole plate through capillary action. It is also good to hang it in case the foundation is in and out a little. Its not a piano, its a foundation. In the old days before pressure treated lumber, we used to put in a termite shield, which was basically a strip of aluminum flashing that covered the top of the foundation and bent down on the outside. This acted as a drip edge. Nobody does that anymore. It made too much sense. 

Is this for your playhouse, your shed, your Garage, or your house? Did that framing book that MJ was going to send you get there yet? I bet this very thing might be in that book. :whistling2:


----------



## markharmon (Apr 24, 2013)

jagans said:


> Who cares about the gap? Bugs need a place to live too. Gary told you the reason for the gap. Its so wicking does not occur. A drip edge is formed, so water dosent travel to the sole plate through capillary action. It is also good to hang it in case the foundation is in and out a little. Its not a piano, its a foundation. In the old days before pressure treated lumber, we used to put in a termite shield, which was basically a strip of aluminum flashing that covered the top of the foundation and bent down on the outside. This acted as a drip edge. Nobody does that anymore. It made too much sense.
> 
> Is this for your playhouse, your shed, your Garage, or your house? Did that framing book that MJ was going to send you get there yet? I bet this very thing might be in that book. :whistling2:


Its going to be a small playhouse that is why i am asking about the flush rake fascia. All the ones I see have that 3/4" lip. Do they make flush fascia where the siding slides under it?


----------



## hand drive (Apr 21, 2012)

when putting hardie siding as the siding on the wall I always put the foundation plate about 1/2" back from the edge of the foundation and this flushes out the sheathing with the foundation and the the hardie laps down 1" onto it. hold sheathing 1/4" up off of foundation so no wicking occurs etc...


----------



## markharmon (Apr 24, 2013)

hand drive said:


> when putting hardie siding as the siding on the wall I always put the foundation plate about 1/2" back from the edge of the foundation and this flushes out the sheathing with the foundation and the the hardie laps down 1" onto it. hold sheathing 1/4" up off of foundation so no wicking occurs etc...


Here is another thing I see that I dont understand. When i put up my soffit panels and attach a j or f channel to the end wall how do I get my vinyl siding into that channel as well. I see pictures of soffit and vinyl siding and I only see one channel for the soffit.


----------



## hand drive (Apr 21, 2012)

markharmon said:


> Here is another thing I see that I dont understand. When i put up my soffit panels and attach a j or f channel to the end wall how do I get my vinyl siding into that channel as well. I see pictures of soffit and vinyl siding and I only see one channel for the soffit.


a lot of times you work the soffit panels from one side and slide them down the line, leave a cornice off of one side of overhang and slide in your soffit panels there and once the soffit is all filled in put on your cornice.

oops, edit. I think you use another J up side down for the siding and another facing the soffit for the soffit- been so long since I've touched vinyl siding... there is the little termination piece that works at the top of a cut piece of vinyl siding also that laps up into the J channel.


----------



## GBrackins (Apr 26, 2012)

markharmon said:


> but what if I choose brick.


sorry Mark I missed the question in regards to brick. if you wanted to have real brick then your foundation typically would have a brick shelf. This is typically (depending on your brick, air space and any rigid insulation board) 4" so that the foundation can support the brick.


----------

