Movement & Expansion Joints

[GazTech]

Many suspected adhesive failure calls I visit, leave out vital expansion or movement joints where they are required. Where a customers concrete base extension meets the suspended timber floor of the original house, and vast meterage of flooring on top of UFH. There are a few ways in which these stresses can be relieved from the flooring, enabling the tiles to move freely without either 'tenting' or cracking across the point of movement. Please state wether you do or dont use expansion joints, and which type you use and why.....Gaz

Tenting as a result of expansion stress

[grumpygrouter]

I have never had a floor large enough to require intermediate expansion joints yet but I do leave an expansion joint round the perimeter and use silicone as the medium.

[Dave]

This is getting quite a regular problem ...At the moment we are hearing more and more of these failures as gaz knows i passed one onto him just yesterday where a £3000 job has failed ....

[GazTech]

This is getting quite a regular problem ...At the moment we are hearing more and more of these failures as gaz knows i passed one onto him just yesterday where a £3000 job has failed ....

Hence my poll & bringing this subject up Dave, I think we should focus on this problem a little more on the forum...

[Dave]

Totally agree gaz......

This makes a good read and hopefully will help fixers etc more clued up...> HERE <

[andersontiling]

I have recently have 800m2 fail.the expansion joints placed every 5 lm..25 m2 grids.the problem seem to be residual movement caused by existing construction joints affected by rising damp.it is important to install expansions even if a cut tile has to be incorporated in the tiling mirroring the joint in the slab etc

jon

[GazTech]

I have recently have 800m2 fail.the expansion joints placed every 5 lm..25 m2 grids.the problem seem to be residual movement caused by existing construction joints affected by rising damp.it is important to install expansions even if a cut tile has to be incorporated in the tiling mirroring the joint in the slab etc

jon

Good point jon, if expansion is already incorporated in the substrate, it needs to be transferred through to the surface tiles...pointless having it expand underneath but not on top......Gaz

[pjtiler]

I have recently have 800m2 fail.the expansion joints placed every 5 lm..25 m2 grids.the problem seem to be residual movement caused by existing construction joints affected by rising damp.it is important to install expansions even if a cut tile has to be incorporated in the tiling mirroring the joint in the slab etc

jon

very important point there jon
i,m surprised it wasn't on the drawings or architects specifications
newbys take note!!!!

[andersontiling]

PIC OF EXPANSION JOINT WHERE SO MUCH MOVEMENT HAS OCCURED THAT IT HAS PUSHED THE NEOPRENE INSERT OUT OF THE JOINT

[Dave]

Wrong joint used then..imo....joints come in varying widths allowing for more expansion in the substrate....

Differing types can be found here.... Movement Joints, Expansion Joints And Control Joint Profiles - Schlüter-Systems

[davy_G]

Im doing alot of new sunrooms coming out of large kitchen diner areas. The new sunrooms have a new screeded floor and i always try and persuade the client to let me put an expansion joint in along the join as i tile the whole thing.
Some say no way it will ruin the look, i point out that cracked grout or worse in a few years will be alot worse!!
Most are happy as long as they are not too visible. I run into problems where they are having a pattern put down and use grey silicone like grumps.
I use from the schluter range, not cheep but good stuff.

[Dave]

Along with this....very useful info...

Where Should Movement Joints Be Fitted?

The theory is to create "tile fields" large enough to absorb differential movement between the substrate and the ceramic or stone covering -- movement joints must be installed in certain areas and positions to prevent tiles or grout from cracking...and in some cases prevent the tiles from tenting and becoming debonded from the substrate. But the exact positioning of movement joints is vital to them successfully protecting the installation. If they're installed in the wrong place they won't work.
Industry guidelines suggest that the maximum tile field should be no more than ten metres in each direction - but in practice, depending on the individual applications, it tends to be between five and eight metres.
British Standards (BSI) 5385 covers the requirements and methods for movement joint applications. Part 3: 1989-Section 3 - 19.1.1 states that the building designer should assess the magnitude of any stresses and decide where movement joints should be located, having regard to all relevant factors, including the type of flooring, bed and substrate.
While the floor areas to be tiled come in all shapes and sizes there is a general formula for working out where movement joints should be placed.
A circle provides the best configuration for movement joints, because the forces from the centre are equal in each direction. However, in practice, because hardly any floors are circular, it is best to look at square floors and rectangular floors. In a square configuration the ideal field size is where the ratio of the shortest to the longest distance from the centre of the force is approximately 1:1.5 (see figure 1) -- for example 5 x 7.5 metres. Generally, the tile "field" should be kept as square as possible, and where underfloor heating is present, the tile field should not exceed 40 square-metres.



However, most floors tend to be rectangular, rather than square, though. And rectangular shapes tend not to be the best configuration, as the ratio of the shortest to the longest distances exceeds 1:1.5. In the example shown in figure 2 the crack risk is at the centre of the area. If no movement joint has been installed, cracking of the tiled surface is highly likely. In large floors it is advisable to incorporate movement joints forming bays at no more than 30-metre intervals. Each bay is then sub-divided into smaller bays by stress relieving joints not greater than ten metres apart.
On suspended floors, stress-relieving joints should be inserted where flexing is likely to occur...for instance, over supporting walls or beams. And, as always, joints must be situated directly over any joints in the substrate, and at any changes in the substrate, such as timber to screed.
For areas less than two metres wide perimeter joints are not normally required, unless conditions generate stresses which are likely to become extreme, for example temperature changes.

[whitebeam]

I use between wood, screed and door thresholds. When doing printed concrete many moons ago cracking was a nightmare even when putting in controlled joints. The worst area for movement was the corners of a building, So when tiling if there is an L shape room I try and put a control joint from the corner. It's convincing the customer they need them thru there brick patterned travertine

I use schluter, a local independant will order them for me

[andersontiling]

Wrong joint used then..imo....joints come in varying widths allowing for more expansion in the substrate....

Differing types can be found here.... Movement Joints, Expansion Joints And Control Joint Profiles - Schlüter-Systems

this had A 10MM infill compressed to nothing

[deanotile]

If a customer is uncertain about having expansion joints I show them two peaces of a4 paper exactly on top of each other then push one peace forwards by 5mm it lifts of in the centre by 20mm that normally makes them understand the need for them.

[charlie1]

I only ever used an expansion joint once on a recent job and placed one every 5m. What i did was replace grout with matching silicone. 5mm joint

[Branty]

Also, just because there is not an expansion joint in the screed, this doesn't mean you won't need one in the tile field.
If a tile area is large enough, it will have enough thermal expansion and contraction of its own to cause tiles to de-bond.

[TilingLogistics]

Today I think there are more and more failures because not only are there new screeds involved, areas being tiled are larger than years ago add large format tiles to the equation and I think you are asking for trouble.

I used to talk people into Ditra and was knocked for it by other fixers because they felt I was pushing the installation cost up for the client. In truth it was belt and braces everytime, just like tanking IMO. Be safe rather than sorry.

Kev

[andersontiling]

you will see here the schluter aksn movement joints are every 5mm .plan before hand and tell the contractor to saw cut the slab to accomodate the tile grid.easy to work out dont forget your joints and the expansion itself

[andy-p]

how do the spaniards/greeks manage without expansion joints ?? quality hotel i was staying in tenerife last year had 100,s of m2 of large format marble everywhere , virtually tight jointed and not an expansion joint anywhere, the floors were perfect no cracks or lifting at all . you think with the heat there would be a lot of expanding and contractions , same scenario at a greek airport i was at this year, do they know something we dont??

[grumpygrouter]

how do the spaniards/greeks manage without expansion joints ?? quality hotel i was staying in tenerife last year had 100,s of m2 of large format marble everywhere , virtually tight jointed and not an expansion joint anywhere, the floors were perfect no cracks or lifting at all . you think with the heat there would be a lot of expanding and contractions , same scenario at a greek airport i was at this year, do they know something we dont??

Decoupling membranes?

[Dave]

I lflew to rhodes airport and it has been revamped...expansion joints everywhere....recently just been to palma airport and they are repairing loads of tiling due to cracking etc......and yes they have expansion joints....( silicone ) most of them apart from rhodes where they were pre-made type...

Also there temperatures don't fluctuate like ours do and our sub-floors are different in structure...poly base with screed overlays etc etc......but on another note these are BS Standards and not spanish/greek etc standards aren't they......

[TilingLogistics]

The Spanish tend to sink their joints using a type of foam rubber. I tried this earlier this year on an 90M2 installation I put right that had been installed without EJ's and it worked very well.

Kev

[Dave Ramsden]

Ive used them in the past on the big H&M stores. 600x600m tiles with 2mm joints.
Will be using them again in the coming weeks and to the correct requirements due to info found on this forum.

Tahnks guys!

[A11CTU]

Hi Guys first post, regarding expansion joints. You MUST always follow expansion joints no matter what anyone else tells you. It allows the "indivdual" areas to move with the stress and settlement of the building.It allows the floor to "float" and move freely without stress. Also temperature change in certain countries.Regarding what type is dependent on the project and the finish required by the client. I always use schulter or a polysulfide with a foam back fill. In germany we had to leave a 5mm joint to all internal corners as well as to the joint were the walls and floors meet. If you need to know how to silicone to a PERFECT finish let me know.

[handyrabbit]

Hi A11CTU! how do you silicone to a PERFECT finish??

whats your top tips and method??

i'm always open to new ideas and learn something new!

cheers

[A11CTU]

Hello Handy Rabbit, well I could not silicone to save my life. Tried masking tape / lick the old finger you name it, until I worked in Germany. The secret is FAIRY LIQUID and a spray bottle. Try this!!!!! Fill a spray bottle with an inch of FAIRY LIQUID in the bottom. Top up with water and shake.Cut nozzle to required width and silicone as normal. Spray the said FAIRY LIQUID and water along the fresh silicone dont worry if it looks to much water is there. Using the back of your finger nail, take off the excess silicone. IMPORTANT you can now "MOULD" the silicone to a perfect finish. If you have missed a bit re spray to mould. Clean hands with the said spray. Try it. Finally on certain baths I fill the bath with cold water so it drops and splays ( you will see the gap between the bath and tiles open up ) silicone then empty bath, leave as long as you can even over night, perfect a seal as your going to get.PRACTICE MAKES PERFECT. Good luck

[handyrabbit]

top banana!! thnx A11CTU! will try that out shortly!!

[BDS]

I`ve just used the schluter joints as per GazTech`s recommendations and there easy to use and good stuff and not a bad price either a hell of lot cheaper than replacing the whole floor when it all goes pete tong cheers gaz

[GazTech]

Thanks John,
The job I looked at with you only needed a couple of exp joints as there was plenty of expansion under skirtings, and kitchen units. Where the concrete slabs met in the doorway was the most important of all.....Gaz
PS When do we get to see the pictures ?