DIY Doctor UK DIY Forums

Hi im new to this so any help would be gratefull. I decided to take a cupourd out from my kitchen to make it bigger but it left a lip in the floor about 5 mill thick. I decided to try and knock it out and level it off with some self levelling compound. However when i knocked it out the whole base came up with it leaving a whole around the depth of a house brick and approx one meter square. there is some insulation board at the bottom which i guess il leave in and some concrete below that but what is the best way to fill the rest of the hole? plus where the dpc comes up the wall to the bricks it has a few tears in it , does this need to be repaired too? look forward to your replies.steve

The damage to the DPC must first be repaired. An easy method is to use some thick bitumen paint which should be applied in several layers, (you could apply tape to the bach if possible to hold it together) allowing the previous application to dry at each stage. Otherwise you could rake out mortar between the bricks and slip in a fresh piece of Polymer DPC wider than the existing DPC and mortar in in place. The former is quicker and easier but the latter is more effective.
The insulation board at the bottom is probably associated with the DPC and is there to prevent damp and cold from the earth below rising so must not be disturbed; there will be a polythene sheet below acting as DPC.
You can mix your own concrete or buy readymix, probably need about 200Kg of the stuff for that size area. If mixing your own, you need OPC (ordinary Portland cement), water and aggregate (stone and sand). The size of the aggregate can affect the end surface finish so choose 10mm size limestone for flooring. Use a straight length of wood to level, dragging this across to get it flat and finally finish with a float.
Check the following link on this site which I have just discovered, it's all explained for you.

https://www.diydoctor.org.uk/projects/mi ... ncrete.htm

thanks for your help. the base of the hole is as i say about the thickness of a brick but then its concrete at the bottom and the dpc is under there so i guess the board is just for insulation. i wont go down any further i shall just try the bitumin on the small splits in the dpc that go up the wall. then concrete it thanks again m8