expansion joint

[howard]

I'm starting a job on monday 36sm2 floor half the floor is concrete half is floorboards the problem i have is where they meet they dont run in a straight line some of the floorboards have been cut around a concrete block so there is no chance of putting an expansion joint there what can i do
cheers
Howard

 

[Turkish]

Hi Howard, i think you will have to have an expansion joint ptherwise trouble looms! You can buy pre made joints from Schluter i think that you can place and cut tiles up to. Hopefully someone with more experience will be along soon to either back me up or shoot me down in flames. Never had to do an expansion joint yet.

Turkish

 

[brian c]

hi howard,without seeing the job it sounds like you might need some ditra matting or some overboarding to do m8,you might however also need an expansion join aswell better safe than sorry m8.

 

[DHTiling]

Howard ...post a pic of the joint.....then we can decide which way to go.....you will need a movment joint but need to see what you are up against.......

 

[JEC-CTD]

A picture would be very helpful.

Its not just the expansion but also the differing stiffness in the two materials that you have to contend with.

 

[howard]

hi lads i dont have a picture the best way to describe it is the concrete has been laid like the letter F hope this makes sense

concrete this side of it F then floorboards this side

 

[howard]

any advice guys ?

 

[JEC-CTD]

I think Ditra matting would be good for this application but ask here [email protected]

 

[DHTiling]

If you have any movement between the timber and the concrete the an isolation membrane won't work......Ditra is designed to isolate lateral movement and not deflection. Howard i would try and straighten the joint up by cutting the timber side straight ( i.e removing the " F " from the floor) and infill with concrete.
Then put the movement joint where they meet and then use Ditra to isolate the stress between the floors , but still continue the joint through the substrate / Ditra and tiles........

good luck......

 

[JEC-CTD]

It would be good if you can do as Dave suggests but I suspect that replacing the timber section with concrete will not be easy if the timber section is a typical suspended floor. If it is suspended then how big is the gap underneath, overboarding may be one solution but as Dave said I believe it is the deflection that is your biggest problem.

Pictures really would help to give an informed opinion rather than us all guessing at the construction of the floor.