Scarifying a concrete floor

downshifted

We have taken up Marley type tiles from our bedroom (there has been damp and some of them were lifting). They were laid on bitumen and it is now patchy and we have been advised to scarify the floor to get rid of it.

Has anyone else had to do this and if so, what did you use? A belt sander won't cope

Thanks

downshifted

downshifted

I've looked on a hire site and they do a "floor grinder" that seems to be right for the job - about £100 for a weekend hire - has anyone used one please?

keystone

Have you tried chopping it off with a floor scraper?

Have you though of just screeding over the top?

What flooring are you planning to put down when you've finished?

Are you quite sure that its the tile addy and not a liquid DPM?

Cheers

downshifted

Hi - thanks for the reply. Scrapers wont work. Chipping with a chisel works but is slow and leaves craters. We've been told we should get rid of it as bitumen is not used in housing now. they think the bitumen was originally laid on damp concrete back when the house was built in 1960 and now that it has been disturbed the damp is drying out - we plan to carpet eventually.

optimus_primera

downshifted wrote: »

I've looked on a hire site and they do a "floor grinder" that seems to be right for the job - about £100 for a weekend hire - has anyone used one please?

If it was the HSS site then .......
No, you will need a Floor Scarifier,the grinder uses abrasive blocks, and will get coated in the Bitumen and not work.
Scarifiers have 2 or 3 steel brushes that rotate underneath and don't tend to get blocked, therefore are recommended for 'chemical' type coverings as opposed to concrete,plaster etc etc

*Chemical = paint,resin,adhesives etc etc*

dave82_2

Check out this post where I raised a similar issue. I found a few products that should do the job but haven't chosen one as of yet.

https://forums.moneysavingexpert.com/discussion/2759178=

Cheers Dave

downshifted

andrew-b wrote: »

Upto about the time your property was built the only form of damp proof membrane (DPM) in floors was often thermoplastic (marley) floor tiles stuck on with bitumenous adhesive. About that time polythene membranes started to be used. If you had damp problems already they could theoretically get worse having removed the tiles.

Why i know this is because our place is about 1955/6 built with thermoplastic floor tiles stuck down with bitumenous adhesive and i've established by excavating part of a floor that there is no other DPM. Fortunately we are on chalk so the absence of other form of DPM doesn't seem to be an issue. On clay it might be a different story!

I removed these tiles on our bathroom floor (note they contain fairly minimal traces of asbestos so best to avoid breaking any more up..when removing spray with water, remove whole, wear a suitable mask/gloves etc and seal off the room and dispose of by bagging up and taking to council tip in the place provided for asbestos).

As for removal of the bitumenous adhesive...beyond mechanically breaking off the surface of the floor by whatever means the only real way of removing it is to heat it up with a heat gun and scrape it off...but it will turn to a really sticky mess and you will wish you never started it and had just stuck the loose tiles down (i've done this elsewhere with no more nails!). However we haven't had a floor covering in our bathroom for a couple of years and over time the bitumenous adhesive is gradually wearing down! I wouldn't suggest leaving it for years but it's a hell of alot easier than trying to scrape it off! your better off leaving it there IMHO.

There's no real reason you need to remove the bitumen if your laying carpet...indeed most floor covering can be laid straight on top (even tiles with the right adhesive). You could alternatively pour a suitable latex-based self-levelling compound down on top....check suitability with the manufacturer.

Edit: i should add my building surveyor/father advised me on my floor and has prodded around with his protimeter to give an indication of whether damp is evident...his happy it's not a problem so that's good enough for me.

Andrew-B

Thank you so much for this - I think we are in exactly the same position and it is a huge relief to find someone who understands the problem.

The bungalow was built in 1960. We took up the marley tiles in the bedroom because there had been damp coming in from a wall (blocked cavity, now resolved) and they were lifting anyway - now we wish we hadn't! We took them up in the kitchen because we had a new kitchen fitted and we didn't know any better! Original flooring (some tiles, some parquet) is everywhere else - and we won't be touching it!

We are on chalk too - Kingsgate, Broadstairs. The damp appears worst in the kitchen - elsewhere we are told we could lay carpets - although I'd like to find an underlay that is breathable. In the kitchen we have been quoted £1500 plus VAT for a dpm and vinyl tiles.

I think we will take your advice and leave the remains of the bitumen. This forum appears to have been more help than the independent damp expert from whom I am still awaiting a report! I am very grateful.

downshifted

dave82 wrote: »

Check out this post where I raised a similar issue. I found a few products that should do the job but haven't chosen one as of yet.

https://forums.moneysavingexpert.com/discussion/2759178=

Cheers Dave

Dave - thank you very much for this - we will study your very interesting thread and try to decide whether to put something else down onto the bedroom floor over the old bitumen - I think we will ask the carpet fitters what they think about the level of the surface

"Experts" have been telling me that if the house was theirs they would not hesitate to lay carpets now.

Do let me know how you get on - and I'll post what we do - it might all help someone else in a similar position

Cheers