Removing bitumen from concrete floor

shellyd_3

I am wanting to put down UFH then ceramic tiles. I have a thin layer of bitumen infact it's just like paint in some areas, so nothing to use a scraper on.
I went to Topps tiles thinking I would be able to put down a layer of BAL mulit base, but they wouldn't recommend this and said the bitumen needs to come up. I have tried a hot airgun, also tried white spirit and lots wire brushing. It's comming off but very hard work. would anyone have a better idea.

Thanks

Michelle

Alan_M_2

Nothing wrong with putting a screed down over the top of that, Topps really don't know what they are talking about, the amount of poor advice that company gives is criminal. The Bitumin is resonably likely to be a DPC for the concrete substrate, leave it intact.

However, I'd be more tempted to glue down an insulation board which will make your UFH at least 60% more effecient, 10mm Lux Board or Aquapanel Thermal.

Stick this down with rapidset flexible adhesives, this creates a barrier between the DPC, fit hte UFH, then fit your tiles. remember you'll require flexible adhesives and groout for the entire project.

shellyd_3

Thanks Alan, I am worried incase it is a DPC like you said, It has worn away in some places so only the concrete showing, also the imprint for tiles are left on the concrete and in some places it is very thick, which made me think it was Bitumen. We used to have a floor boiler and where it was the concrete is clean. I would like to put down the thermal boards but haven't got the 10mm to spare, or the extra £200. So I will have to go for the screed or keep scrapping once I am sure it is Bitumen. My house is 30-35 years old would you know if it was standard practice to put this type of DPC in then?

Thanks for your reply

Michelle

a-builder-A1

probally been laid to combat a damp problem, if in doupt screed

Volcano

My house is of a similar age and has bitumen DPC. You can get bitumen-like waterproofer from DIY shops to repair your DPC if you've scraped too much away.