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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> BAL Multibase https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1148114098 Message started by AndyOlds on May 20^th, 2006, 9:34am

Title: BAL Multibase
Post by AndyOlds on May 20^th, 2006, 9:34am

Hi,

Probably a stupid question, but...

I am going to be using BAL Multibase as a base for the tiles I am gioing to install on my bathroom floor, to set an underfloor heating mat into. (This was recommended by JasonB in a reply to a post I made quite a while ago).

As I've never used this stuff before, I have no idea what consistency it is going to be when laying it. As my tiling will end once it gets past the bath panel, I want to know if I will need to use some sort of batten to hold the edge of the Multibase until it sets. If it's going to be really runny, it would otherwise run out of the required area and under the bath!

Also, should I lay enough to just cover the surface of the heating mat, or build it up a bit thicker? This is going on top of Aquapanel concrete sheets, by the way.

Title: Re: BAL Multibase
Post by jasonB on May 20^th, 2006, 1:32pm

It's worth making a "dam" as by its very nature the leveling compound will flow to its own level. You only need a scrap of batten tacked to the floor or wedged from the underside of the bath.

It is possible to alter the consistancy by varying the amount of water but as it's your first time measure out the correct amount stated on the bag. If you are using the mat backed coil it helps to keep the mix runny, you can get away with a thicker mix if it's just the loose wire being used.

The aquapanel will not suck the water out as fast as if you were laying onto ply so the multibase will flow further.

You should be aiming to get the multibase level with or just above the top of the wires.

Don't forget to check the resistance of the wire before laytexing and throughout the tiling process so any damage can be spotted early.

Jason

Title: Re: BAL Multibase
Post by AndyOlds on May 20^th, 2006, 7:40pm

Jason,

Thanks for the reply. I got the aquapanel and heating mat laid today, so I'm going to try the multibase tomorrow morning.

I had a bit of an anxious moment when I checked the resistance of the mat after I'd laid it and it showed open circuit. Turns out I'd just got the multimeter on too low a setting. :P

I didn't actually realise that multibase was a self-levelling compound! Good job I posted the question. Will I need to smooth it out with a float at all, or is it so runny that you just pour it on and leave it to settle on it's own?

When you mention latexing, are you referring to the multibase, or is there someting else I should be laying on top of the multibase before the flexible tile adhesive?

Also, how long should I leave it before beginning the tiling?

Thanks for the brilliant pointers so far.

Title: Re: BAL Multibase
Post by jasonB on May 21^st, 2006, 8:42am

It will mostly flow to cover the whole floor but you may find it needs a little help into the corners and to get it all around the mat. A float or the smooth edge of your tiling trowel will do.

Laytex is just another term for self leveling compound, comes from when most were a two part mix of powder & liquid laytex.

Should be firm enough for light foot traffic in 3-4 hrs and firm enough to tile in 4-5 but will depend on temp, thickness and consistancy of the mix.

Jason

Title: Re: BAL Multibase
Post by AndyOlds on May 22^nd, 2006, 12:49pm

Cheers Jason.

Got the multibase down yesterday morning - seemed to go very well.

I could do with an 'assistant' to do the mixing though - takes absolutely ages to do to avoid lumps!

Title: Re: BAL Multibase
Post by jasonB on May 22^nd, 2006, 5:58pm

One of thesein a decent cordless will mix it up in no time, get one for the adhesive.

Jason

Title: Re: BAL Multibase
Post by mudster on Jun 9^th, 2006, 12:43pm

What you've done probably won't cause any problems but for future refernce don't use BAL Mulitbase on timber floors, it's only designed for non flexing substrates. In fact BAL don't make any products suitable for screeding wood, including Acrybase.

The only self levelling compund I'm aware of that is suitable for use on timber is produced by Ardex and known as Arditex.

Title: Re: BAL Multibase
Post by jasonB on Jun 9^th, 2006, 5:42pm

Mudster, BAL suggest Multibase to set the mat in when overboarding with ply or aquapanel, see page 19

http://www.bal-adhesives.co.uk/bal/main/pdfs/fixing_guide.pdf

Jason

Title: Re: BAL Multibase
Post by mudster on Jun 9^th, 2006, 8:37pm

Read the spec again Jason, that's concrete floors only.

I phoned BAL this afternoon just to double check as it appears they are suggesting that Arybase is suitable. Their technical guy stated "BAL do not produce any screed compounds suitable for use on wood".

Arditex really is the only one I've ever found.

Title: Re: BAL Multibase
Post by jasonB on Jun 10^th, 2006, 8:07am

Thats interesting , The printed guide clearly suggests Multi base but the pdf shows Acrylbase(bottom of page) but the line does not point to the screed layer.

Think they have been altering their specs? Will give them a call myself Monday and see whats right.

Jason

Title: Re: BAL Multibase
Post by mudster on Jun 10^th, 2006, 12:13pm

I found that BAL moved the goal posts on a couple of their products.

Their wide flexgrout that's now been replaced by supergrout was a known failure, I saw an off the record document to the retailers telling them to withdraw the product immediately due to multiple failures, yet they denied it when questioned and wouldn't entertain any claims for the failures.

Personally I'd prefer to use everything from Ardex, but it's plainly too expensive and difficult to get hold of.