Home>Discussions>EXTERIORS>Gap between foundation and OSB sheathing
8 posts / 0 new
Last post
genuser
Gap between foundation and OSB sheathing

I am planning to replace damaged vinyl siding on the house. It's the lowest row. The house has 1/2" OSB sheathing on it. It was built in 1999 (Minnesota). There is no WRB wrap on the sheathing. Also there is no flashing covering the gap between sheathing and foundation. The starter strip is flush with the bottom edge of sheathing. I read somewhere the starter strip should extend 3/4" below sheathing edge and cover the foundation.

I don't think I can lower the starter strip, or it would mess up the panel lines.

Should I now apply house wrap and insert some sort of flashing to cover the gap? What kind of flashing would be appropriate?

Thanks

dj1
Re: Gap between foundation and OSB sheathing

Your house is about 15 years old, and it looks like it has some serious code violations, which is somewhat surprising for a house this young.

To bring the house up to code, you'll have to do more than you are describing.

Not knowing your level of expertise, you might have to get some professional help for some of the issues you have.

HoustonRemodeler
Re: Gap between foundation and OSB sheathing

A chat with the local building authority would be very helpful.

Mastercarpentry
Re: Gap between foundation and OSB sheathing

What you've read is correct, but if you lower the starter strip everything above it drops too, so you're going to have to R&R all the siding adding new where needed if you do that.

However, you can use flashing to remedy this without moving the starter strip vertically by bending fascia metal to drop over the foundation joint at least 3/4", running horizontally to the outer corner of the OSB, then vertically up the wall under the starter strip which will go back where it came from. It will be visible but based on the layout and the color of the metal you may hardly even notice it. Not the 'right way' to repair this but it will work and meet code requirements in most places and it's a whole lot less money and fuss :)

Phil

genuser
Re: Gap between foundation and OSB sheathing
Mastercarpentry wrote:

What you've read is correct, but if you lower the starter strip everything above it drops too, so you're going to have to R&R all the siding adding new where needed if you do that.

However, you can use flashing to remedy this without moving the starter strip vertically by bending fascia metal to drop over the foundation joint at least 3/4", running horizontally to the outer corner of the OSB, then vertically up the wall under the starter strip which will go back where it came from. It will be visible but based on the layout and the color of the metal you may hardly even notice it. Not the 'right way' to repair this but it will work and meet code requirements in most places and it's a whole lot less money and fuss :)

Phil

Phil, thank you for this suggested solution. I found a product at local Home Depot that could work. It's pre-formed so I don't have to rent a brake and try my hand at trim coil. I am not a pro. Amerimax Roof Apron (product id: 5507500120). I can nail it to the OSB and flatten it over the foundation.

They also have a Gutter Apron. Similar profile. Priced higher.
Any opinion on this product to solve the problem?
Thank you.

genuser
Re: Gap between foundation and OSB sheathing

Phil. thank you for the idea. I actually responded before but that post never appeared. I think it is because I put a URL in that post. Now, I can't find it anywhere.

I am thinking of using an aluminium Gutter Apron to flash over the gap. It will save me from slicing a trim coil. These are about 5-6" wide, pre-colored, and the edges are hemmed as well. It's a little expensive. However the gutter apron is angled. I can place it like a tent over the gap and flatten it out when I nail it to the OSB. Put house wrap over it and nail the siding on top. Do you think a flattened gutter apron will work?

Mastercarpentry
Re: Gap between foundation and OSB sheathing

Maybe, but nailing and un-straight surfaces can introduce waviness in the finished appearance so it's better to have the right shape to start with, custom-fit to the situation. If you want to try the gutter apron buy one piece and see how it goes, then if you like it complete the job that way. Either way let us know the results.

Phil

genuser
Re: Gap between foundation and OSB sheathing

Attached a picture (zip file) in post#1 to illustrate the problem.

Thank you for the suggestion Phil. The weather is warming up again. Time to get back to outdoor projects.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.