Filling Block Walls

[Dann]

I just finished a short retaining wall in my basement (7 blocks tall by 5 blocks long) the cells of which I was going to fill with cement (7 cells each with rebar) The footing is the concrete basement floor which is only about 1-1/2" thick. Will this be too much weight? Is there a "lighter" filling I could use instead of cement? The previous owners had constructed longer retaining walls along the other end of the basement which appear to be filled and there seems to be no problem. Any advice is appreciated. Thanks.

[Rich]

1.5" thick :shock: that's not much for a slab. There is a lighter filling - mortar/grout.

[Dann]

It's an old house (circa 1922) and the basement was built, I believe, to accomodate a gravity furnace. It's only about 100sq feet. Is the mortar you are referring to the mortar I used for the wall or is it a special mix?

[Rich]

Same mix. You can make it a little wetter so it'll have fewer air pockets in it.

[Dann]

Thanks for the help

[doyle]

I'm not much of an expert when it comes to masonry, but it seems to me that your concern about the weight is a valid one that may need exploring further.

I don't think that a 1-1/2" concrete floor will hold up that much weight. You may want to bust up or saw an area out of the old floor and make the concrete deeper so the new retaining wall will have a stronger footer.

[Dann]

Unfortunately It is already built just waiting for me to fill it. The previous owner had constructed walls and the floor seems to be holding up although I should have broke out the floor and pored a deeper footer.