Rim Joist Open to the outside

[Rob Long]

Hello-First time poster here. Really need some advice on the following situation: Looking to have basement level finished. All rim joists are packed with R-19 batts. A few of the batts looked like they had shifted, so I pulled one out to readjust it. When I pulled it down, the cold air came pouring in like I had opened a door or window. Upon further inspection I found that rodents have also been visiting my basement ceiling area. More specifically, it seems our builder used a poured concrete wall with a full width brick ledge to grade. However, the brick ledge was not installed until some time after framing was completed (i found the pictures). So the baseplate or sill plate is sitting on the concrete wall, but the bricks do not meet the concrete at the same height. In turn, my TGI floor joists are actually cantilevered over my foundation wall by about four inches our so and the band board is not resting on top of anything. I can actually work my hand to the outside by applying pressure to the J channel of my siding which just slightly covers the top most brick of the brick ledge. How should this be fixed? Even if I fill the cavity from the inside, the brick ledge remains a shelter area for vermon! Thoughts and ideas are most welcome. Pics are attached showing obvious air flow over the insulation.

[John Kogel]

We need a pic of the outside. Can you slide in a flashing?

[Rob Long]

Adding pictures of the outside as well as another from the inside. The siding overhangs the brick by about two inches. The tail of the flashing you see is due to a cantilevered bump out that is not shown, which forms the bottom soffit of the bump out. Do these pictures clarify my post? Thanks for reviewing.

[Kristi Silber]

Hey! That looks just like my rim joists looked! I "fixed" mine before I had any knowledge of building with boards and caulk and foam insulation. It's possible I'm harboring a bevy of beasts back there, but they haven't gotten into the basement in 7 years.

[Robert Ernst]

The batts are not going to do much for you here. Spray foam would be the best bet. The next best thing would be to use board insulation the outside face of the rim and seal the edges with caulking and foam. If your building new interior wall You would also need to insulate the bottom of the floor to over the top plate of the new finished wall. Blocking over the new wall and sealing it would prevent cold air from making it's way under the floor above.

[Thomas Jones]

Rim Joists? I see a sill plate with I joists sitting on top, and OSB sheathing attached to the ends. How well do you know this builder?

[Rob Long]

Well enough to call him to come out, though not sure he will agree...built the house seven years ago. At the least, I guess I am looking for some sort of validation this construction is wrong and very farm from any acceptable practice.

[Scott Patterson]

I do not know of a simple repair for that. Is it wrong? Well, it ain't right!

I think that I would get with a good foundation contractor and or an insulation company that specializes in foam insulation. This might just be a good candidate for a closed cell foam treatment.

[Kerry Staudt]

Since the rim joist does not rest on the foundation, should squash blocks be installed at each joist?