Cellar floor + concrete

Discussion in 'Builders' Talk' started by kamy, Feb 26, 2007.

  1. kamy

    kamy New Member

    My cellar floor is currently laid with flagstones - the floor is very uneven with a lot of damp. I have 2 quotes to lay a concrete floor (seal with dpm, 5 inch concrete floor etc).

    The first builder told me that I should lay the concrete over the flagstones - the floor is very uneven and my worry is that the concrete will settle over the flagstones and I will end up with an uneven floor. He also told me that if I remove the flagstones then moisture will enter the new concrete floor! (I thought that the dpm would minimise moisture!).

    The second builder told me that he would remove the flagstone and then lay concrete.

    Which is the best method according to the builders on this forum??

  2. The Brickie

    The Brickie New Member

    Take up and lay new the best option, save the flags tho cos original flags are worth a small fortune.

    Might not stop the damp tho, you may have to 'tank' the cellar to stop water penetration thru the walls. You need to do all the works in one hit to provide a continuous seal, ie to form a tank inside the cellar.
  3. tph1

    tph1 New Member

    both methods could be right - if installed correctly. If laying over existing, is the floor stable enough for concrete topping? Concrete can easily be levelled, and if thick enough, with the right mix, should not break up. HOWEVER, it may not leave you with enough head room... obviously removing flags first is the more professional option though
  4. Bcountry

    Bcountry New Member

  5. Bcountry

    Bcountry New Member

    Forgot to say I managed to get rid of the old quarry tiles from the floor which put £150 into my beer fund!
  6. kamy

    kamy New Member

    The floor is very unveven with some of the stones dropping by 7 to 10 inches near the outside wall - The soil underneath is very wet - I will be laying a 5 inch concrete on top - can this wet floor support the concrete?

    The reason I ask if I should remove the flags is because my friend removed the flagstones then laid concrete in his house - now there are alot of damp patches on the concrete meaning that damp is rising from the floor. Maybe it was a botched job or something.

    I would think that laying a double or even triple DPM would be better than single DPM?

    The million dollar question - is it more likely for damp to rise without the flags?
  7. kamy

    kamy New Member

    Good job Bcountry! I like what you done on the stairs - my stone steps look ghastly - how did you do the stairs? - what materials have you used? What do you call that metal strip!
  8. Bcountry

    Bcountry New Member

    The stairs are simply ply on batons to allow air under. On top of the ply are carpet tiles. The trims are just alminium angles purchased from BnQ. It was a rip off but cheaper than proper stair nosings. I think it cost about £8 for 1.5mtrs. I have added photoluminescent (i think thats how you spell it!) strips on top of the trims - these are textured for a good grip. These glow in the dark so if we lose the power we can get out of the complete darkness! This also hides the countersunk fixing screws.
  9. Bcountry

    Bcountry New Member

    Fortunatley my floor - after I removed the quarry tiles and ash base was clay so it was solid but slightly damp. The night before the concrete was laid we had to remove around 5inches of this clay and hump it all up and out into the garden - a bugger of a job. Anyway, my point is that after we had done this the floor was damp and very uneven as we were pick axing out the clay. The concrete was mixed fairly wet and took a good week to fully dry out but because it was wet it natually found a rough level. If your not happy with the final level you can always throw some self leveller onto it after.
    Do you have the ledge as shown on my pics around your room? If so take the dpm up and over this and return up the wall about 100mm.
    As for removing your slabs down there- firstly will you have enough head height if you dont remove them? Secondly damp will come up if you have slabs down or not so that shouldnt be an issue. I imagine the slabs are damp most of the time at the moment.
    Thirdly add ventilation down there whatever you are doing. This is the most important thing you can add. It will help prevent damp from building up in the air.

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