Filling in holes in my concrete floor

Kashkai

I had several trenches dug in my hallway to find the source of a leak in my central heating pipes. The plumber won't come back to fill in the holes he left. Can I just fill these trenches (6 inches wide by 4 inches deep) with sand which I'll compact to leave a solid base upon which to relay my wooden floors? My thinking is that if the pipes were to leak again at some point in the future, it'd be much easier to dig up the sand than concrete or would I be leaving myself open to pests taking up residence in the sand?

michael999999

make sure you lag your pipes then fill the holes with concrete.make sure none of the pipes are exposed before you back fill the holes with concrete or it will burn the pipes.i wouldnt just fill them with sand or you could have a rodent run through your home.

Kashkai

I plan to lag the pipes before back filling. Due to my leaky central heating system, I was reluctant to fill in the holes with concrete in case it had to be dug up again.

As concrete shrinks when it dries, how would I ensure that the new concrete bonds to the old concrete?

PaleRider

Hello Dave, Sorry to hear about burst pipes, not to pleasant. If you are going to fill the trench yourself, here are a few tips you may like to follow. Before filling out with Screed, could you do the following.

1. Hoover out the fine dust in the area to be worked on.
2. Lag pipes
3. Use a PVA glue or similar to coat area to be worked on, bottom and sides.
4. Compact screed into area, and around pipes. Do not disturb pipes to much.

Sand cement is just normal fine sand & cement, Semi Dry, mix ratio, 4 sand & 1 cement. Not to much water. Use fine batten to level top.


Regards

Kashkai

Thanks for the tips. Sounds easy enough to do.

Appreciate the help.