asphalt floor/sulphate attack

[steviep001]

Hi all. , Don't know who to talk to about this so hoping somebody here can help.
My house was built in the forties and has a asphalt floor.The floor has started to get lumps appearing in it, and 1 skirting board is showing signs of damp. I've been told its sulphate attack because the place I live used to be a mining town. 1 builder told me the only option is to replace the complete floor throughout my home. I was wondering if there's any other options. Any help would be greatly appreciated.

 

[tony1851]

This is a recurring problem with some houses built with solid floors in the years after the War. Sulphates in the hardcore react with a by-product of the cement in the slab, forming crystals which expand, causing the slab to lift.
The only effective solution is to remove the slab and hardcore completely (the concrete will be contaminated) and re-lay the floor on new hardcore, with a dpm and suitable insulation board.

 

[steviep001]

Thanks for the reply. I was hoping there was another way, or a way of finding out for sure if it is sulphate attack. I live on a small grove with only 12 houses and mine is the only one with an asphalt floor all the rest are just concrete. This is what puzzles me.

 

[^woody^]

If the lumps are small (hand size) then it could just a a damp issue.

If they are much wider, more of a hump in the floor and some cracking, then it could be sulphates

You can get the floor drilled and the concrete tested for sulphates - consult a structural engineer

Any susceptible property can be affected at any random time, and similar neighbouring properties could remain unaffected. Normally the cause is a sudden increase in ground water - perhaps the recent rains, or it could be a broken drain, so you might need those checking

You would normally need the whole floor replaced. Depending on the levels of sulphates and risk to the foundations, it may be possible to leave the hardcore in and just renew the concrete, otherwise the whole lot needs to be removed

If you are the only one with an asphalt floor then, it was either built like that or done later to remedy a damp problem

 

[steviep001]

Thanks for the advice again. Before pulling all the floor up I'm going to core drill one of the lumps to c what's happening below it . If the slab is undamaged then I'm thinking of lifting all the asphalt,laying a liquid dpm and self levelling over the top. Any problems with this,would I be wasting my time.