I have a CMU foundation block wall in my garage that leads to my basement (picture below). Half of the cores are empty and it is about 8-9ft deep. I regularly treat this area and the garage with bifenthrin insecticide, but the open cores are continuing to attract tons of camel crickets to use as a home. I'm currently renovating the garage so I want to either either fill, cap, or finish the top of this wall off so it looks more attractive and eliminates an area for insects to live. I'm looking for suggestions on the best way to do this.
This foundation wall is from 1956 and half the cores are already filled. If I end up needing to fill them, I can do this by hand with a wheelbarrow and 5gal bucket and I was looking at Sakrete Maximizer Concrete Mix since it seems to yield the most fill per 80lb bag. The fewer I have to mix, the better. I would eventually seal and paint these walls leading down the stairs. Thanks!
Update:
This went well. Looks more finished now and the camel cricket numbers are dwindling. I screwed some 2x4s to the wall to make a form and only ended up needing about two and a half 80lb bags of concrete mix after filling the blocks with broken up pieces of rigid foam.
Best Answer
To insect proof the block, you only need to fill the last 4" of block. Stuff newspaper in the core down a ways to keep the concrete of masonry mix from dropping all the way down.
Filling the whole core is not needed and to attempt to fill it from the top, through those small holes will only be frustrating. It will not go all the way down anyway. It will stick to the sides and other cross webbing you do not see and start collecting in places before it gets to the bottom.