Tile Adhesive Flexibility Explained - Bag Adhesives

[Dan]

In the attached image, very roughly done in paint might I add, you'll see the 4 main flexibility strengths for mainly cement based adhesives, or usually in bags, although not always.

Standard (the first block): These adhesive are the basics, a touch from just sand and cement already mixed for you really, just with a few additives to retain water for the correct length of time to allow the cement to cure etc. Limited on the thickness you can apply them, these adhesives are mainly only used on concrete (very solid) floors. You can usually get a standard setting version which is a 24 curing time, and then a rapid setting version, which is what most traders would us due to the speed they can lay the tiles.

Single Part (the second largest block): These adhesives you will still just mix with water, they are pretty much as above except they have SOME flexibility values. You could use this perhaps on a concrete floor using underfloor heating (as standard would crack and break with the heat). Depending on the manufacturer, sometimes you'll find a single part flexible adhesive can withstand a thicker bed of adhesive, or maybe stick to substrates other than concrete. Always check before you just go for it though!

Two-part Flexible: (the third block): This is usually a standard adhesive, rapid setting or not, that you will buy separate bottle of additive for to make a non-flexible adhesive flexible. This usually gives the adhesive a higher strength of flexibility than a single-part flexible adhesive meaning you can use it to tile to some wood set-ups (e.g plywood overlay). You would use this if you are overlaying tongue and groove floorboards with plywood for example.

Special flexible adhesive (the fourth block): This used to be pretty much just BAL fastflex, so here I'd say, this adhesive is still cement based but has rubber chippings or similar in it to make it flexible, and you would mix it with ONLY the bottle provided (no water).

But now there are more and more special adhesives on the market that you can tile directly to tongue and groove floorboards. Generally the aim with this adhesive to cut out overlaying floor with ply.

But train stations and the London underground use bal fastflex as it absorbs the vibrations from passing trains due to the high rubber content. Factory's have also been known to use the fasflex.

And I'm not too sure if some of the other super flex-adhesives (larsen, toppsfix, weber and the likes) would be the right choice in similar situations so it's probably still fair to say whatever is the most flexible adhesive type is the most flexible, BAL Fastflex will always be one grade higher.

All of this excludes epoxy, which can be used as an adhesive and grout in some applications and is usually the most sticky, flexible, type of adhesive/grout (mixture) available. 'Epoxy explained' will follow soon enough

I've been out of the game for a while, so always double check with the adhesive manufacturer before going off this advice. But this is what I used to tell those I'd teach some time ago.

[Leatherface]

Thanks for the info Dan

If anyone is able to get hold of Mapei adhesives in their area they would be well advised to phone the Mapei Technical Dept in Brimingham - ask for the little black book - gives a technical breakdown of every adhesive they stock.
They have a wide range of flexible one part adhesives that are high grab, non slip, suitable for porcelain & UFH. No need to prime on some substrates.
They do a latex additive - when added to their flexi adhesives it's like s**t to a blanket.

The little black book is so good because it has a glossary that gives you every type of substrate & adhesive - which to use / prime / which additive / which primer / & when to phone technical dept.

Bloody brilliant !!!!!

[Dan]

Seen PowerSpec Online Tiling adhesive and grout specifier ?