HI

I am just about to take up some old vinyl tiles in shower room on a job and it is leaving a thin black residue of vinyl tile glue on the concrete floor.

Am I ok to tile straight onto this with adhesive or should I really look to cover it first with a thin layer of SLC? If so which one etc would be best and is any priming required etc?

Thanks for your help.

Good afternoon scoxon

We would recommend the following;

1. Ideally remove, mechanically, about 80% of the old vinyl adhesive residue, exposing the concrete floor beneath.
2. If you are able to do this using a long handled scraper, needle gun (if appropriate) or other type of suitable mechanical abrasion tool, direct fixing of the ceramic tiles may be carried out using e.g. BAL Supercover Rapid Set or other suitable BAL Adhesive.
3. Priming should only be necessary if the exposed concrete appears to be porous/aborbent after treatment to remove the residues. In this is the case vacuum off all loose dusty material from the surface and prime use BAL Prime APD (Dliuted 1:1 by volume with water).

4. If you are not able to remove 80% of the residue, then providing all of the loose vinyl adhesive residues are removed mechanically and the remaining residues are sound and well bonded to the concrete , apply BAL Acrybase in a minimum 3mm bed depth and allow to dry for at least 4 hours before tiling commences.

N.B If the floor is part of a wet room i.e. water via the shower head falls directly onto it, then it is essential to ensure that some form of waterproof tanking layer is in existance and located within the floor construction in order to prevent water penetration through the floor.

If this is not the case, please contact BAL TAS for further information on the use of the BAL WP1 Tanking System. If you wish to do this via phoen our number is 0845 600 1222 (Professional helpline).

I hope this information is helpful.

Regards

Dave W

Thanks Dave

Is it possible to use Multibase as the spec sheet seems to say that it goes over old adhesive residues. Or does this refer to tile adhesive residues only? Its just that I have some Multibase already or is Acrybase really the one to use?

Also its not a wet room so no worries there.


Thanks.

Hi

Yes if it is not a wet room area, BAL Multibase may also be considered as an alternative. to BAL Acrybase.

Thanks

Dave W

Thanks for your quick response and help Dave.

Why is it ok to use an SLC onto old adhesive residue but not ok to use an adhesive such as Rapidset or Rapidset Flex?

Good question Richard - will find out

2. If you are able to do this using a long handled scraper, needle gun (if appropriate) or other type of suitable mechanical abrasion tool

Iv'e heard that a hammer & chiesel along with an aching elbow, sore back and painful hand blisters are a god send on this type of work

Good luck mate, i had this last week

TJ

So whats the answer?

I would have thought it would be a great surface to go on because that vinyl tile glue is seriously hard to remove so it has obviously bonded to the floor well and because it's already tacky i would have thought that would be an advantage to prime onto and then tile directly over it.

We'll see

tj

Any answers yet chaps?

tj

Not as yet TJ, but I'll add it to the list for the TAS team

Your a good man James

Thanks mate


TJ

'If you are able to do this using a long handled scraper' never been able to do that.

I would of thought you would of said Multibase as the first option as I recent found out that it's got more flex than Acrybase (which I've used for that purpose before).

Good morning Gents

Levelling compounds vs adhesives onto bituminous residues.

In simple terms, adhesives contain more water than levelling compound. Also levelling compounds are designed to have lower shrinkage within the cement chemistry as they are required to be laid at greater thicknesses. Therefore tile adhesives will generally have greater shrinkage. The greater the drying shrinkage movement, the more a pulling force will be exerted onto the old soft flooring adhesive, such as bitumen, acrylic contact type adhesive etc. This will not normally pull up the bitumen soft flooring adhesive residues from the floor base but can weaken them. The more the floor is used i.e walked upon or trafficked, the more this weakened layer is likely to break down leading to tiles de-bonding.

Normally the mode of fracture would be within the bitumen itself i.e:

1. The tile adhesive would be well bonded to the ceramic/porcelain tile.
2. Part of the old bitumen adhesive would be well bonded to the lower face of the tile adhesive.
3. The remeining part of the bitumen adhesive would remain bonded onto the original floor.

Bitumen by nature is a very soft material that is cohesively weak i.e. if a pulling force (tensile force) is applied to it.

In other words the old bitumen adhesive would have broken down within itself (cohesively).

Therefore the levelling compound will reduce the risk of drying shrinkage movement affecting the old adhesive layer.

I hope this helps

Thanks

Dave W

Thanks Dave

Sounds very similar to the reasons why PVA should not be used