Preparation of bitumin floor - Tile Advice

[jafeica]

im going to tile over a solid floor which has a thick layer of bitchumin over concrete. House probably built in the fifties. Tiles are porcelain my question is - What is the best method to prime or prepare the surface for tiling. Will be using topps own standard set addy

 

[Tile Fix Direct]

How thick is the bitumen? is it a waterproofing compound or the remains of an asphalt based vinyl floor tile adhesive?

 

[Qwerty]

Remove any large deposits with a scraper and then prime with a SBR/ cement slurry or use a grit primer (prime & grip or eco prim grip)
Any pics?

 

[jafeica]

How thick is the bitumen? is it a waterproofing compound or the remains of an asphalt based vinyl floor tile adhesive?

its approx 20mm thick so part of the waterproofing for the floor

 

[Qwerty]

its approx 20mm thick so part of the waterproofing for the floor

That is very thick! Has the screed been removed then??? Are you sure its 20mm thick? Photos really would help here

 

[Dumbo]

Are you sure it is bitumen .
I've worked in ex council houses that had a red resin type floor down , I'm sure someone on here will know what that was, I can't remember the name ,

 

[Ajax123]

At 20mm built in the 50s be careful as it could be magnesite. These were often red, green or black and they will not take a tile adhesive or slurry. A quick easy test would be to use an electric damp meter like the ones used for testing rising damp. If its magnesite the moisture reading will be very high or off the scale

 

[Bond]

Might be a bitumen/asphalt topping over a concrete screed.

 

[On one]

Is the colour of the floor black black(bitumin) or a deep burgundy (black pudding) colour?
I used to live in a 50's house, where the whole ground floor was supposedly levelled with a 20mm burgundy coloured coating, matt in colour.

 

[Old Mod]

Is the colour of the floor black black(bitumin) or a deep burgundy (black pudding) colour?
I used to live in a 50's house, where the whole ground floor was supposedly levelled with a 20mm burgundy coloured coating, matt in colour.

That’s called ‘Magnasite’ and is a banned substance now.
It soaks up water like a sponge.
They also used to use all manner of fillers in the product.
The most dangerous of all was asbestos.
It should be removed before work commences.

 

[Old Mod]

Haha I’ve just seen Alan’s post

 

[Just Rizzle]

try reading up on BAL FLEX BONE if the floor is flat and smooth just lay over and tile

 

[Flintstone]

Not if the floor has issues with damp.

 

[Ajax123]

Haha I’ve just seen Alan’s post

Twice is better than none at all... at least that's what my Mrs says... magnesite was dreadful stuff though. Still an awful lot of it out there. It was mainly used in council houses....

 

[Ajax123]

try reading up on BAL FLEX BONE if the floor is flat and smooth just lay over and tile

That's a good point Ray. Would be interesting to see if they would recomend it over magnesite. Cant see why not...