|I have done the same and got two different opinions - one from an |engineer and the other from a builder. | |The builder was worried about expansion and recommended 10mm |polystyrene around the edge of the floor (i.e. between the walls on |the floor).
Right. This was the sort of thing I was thinking about. I suppose it doesn't really matter if I have the gap slightly further away from the walls? (It would suit the way I am pouring it much better if I can).
|The engineer (a friend whose views I would trust) was |worried about contraction. His view was that when concrete cures it |contracts. If it was in contact with the outside walls it could put |stress on the walls. He recommended bringing the DPC up the wall so |that the concrete floor was floating - i.e. did not bind with the |outside walls.
Fair enough. This will be OK anyway as I intend to put a membrane down first and bring it up the walls to stop damp penetration from beneath. I also plan to use a steel reinforcement grid as there may be some heavy traffic in the future.
| Because it was a double garage we put an expansion |joint in the middle using 10mm polystyrene.
Can't remember where you got it from, can you? | |In the end I took the engineers advice. The garage has been standing |for about 7 years with no problems with the floor. | | |Hope this helps | | |Howie wrote: |> Hi all. Hope you guys can help me as previously. |>
|> Having just built a garage (concrete block construction). I am |> about to cast a concrete floor. |>
|> However, as the floor is to be poured inside the walls, I am |> wondering if I need to buid in some allowance for expansion. If |> so, will it be sufficient to use wooden planking as formwork, but |> just leave them in place. (Say, 2 feet from the walls all |> around)? I am assuming that the wood will compress instead of the |> floor pushing outwards. |>
|> Or.. is there a better system? |>
|> Thanks in advance. |>
|> Howard. |>
|>
|> -- |> Howard Coakley |> e-mail... howard