There is the circular hole in the floor in my living room near radiator which leads to a relatively big space underground! If I want to judge using my eyes,I think the size is around 50cm/1.5feet depth and 30cm/1 foot width and 30cm/1 foot length. I think a mouse entered my house through this hole which is man made. I don't know why there is such a hole near radiator.
I cannot completely fill the hole because it opens to a larger space. I want to lay a plastic sheet over the hole and then push the sheet into the hole. Now I have a cup-like plastic sheet inside the hole which I can fill with cement or mortar.
I am wondering which is better, mortar or cement? I think cement must be better because mortar is made of cement itself and sand and lime. Thus I think the cement must form a stronger piece of solid.
I would be happy to know about other possible solutions too.
Here is a photo:
Best Answer
There are two solutions that should be easier and cheaper than cement or mortar.
Cement could certainly work, if you can get it to stay in place while it dries. Get some steel wool, which mice won't chew through, and a can of spray foam such as Great Stuff (there's even a pest repellent version of it available at Home Depot). Stuff steel wool around the hole and fill it in with spray foam, which will expand and can be trimmed with a knife after it dries. This will keep bugs out and the steel wool will keep mice from chewing through, and it's fast, easy and cheap.
Alternately you could get a small piece of sheet metal. Use some construction adhesive to hold it in place and it should keep bugs and mice out.