Looking for advice

[Stef]

I've never heard of such a floor but as Andy says I would go with what's been said already.
I would err on the side of caution.

 

[Dave]

I believe these screeds are meant to breathe... So should it be tiled and should cement based adhesive be used .?

 

[Russell brown]

I've been on the phone all day with various technical departments, Webber don't make anything suitable to use straight onto a lime substrate. Mapie are getting back to me, ardex reckon arditex NA will be suitable if primed with p51 primer and dural say the there matting will work as long as there's no more than 5mm deflection in the centre of a 3m straight edge when held against the floor. I haven't got all the information I'm happy with and im still not sure wether it's worth doing, but I'll continue to look into it as a learning curve as I've seen a few of these floors around here.
thanks for everyone's input so far it's all being taken on board.
Russ

 

[White Room]

The trouble also is the strength of lime mortar/substrate, by the sound off it the property is very old so is the lime and it is'nt a strong substrate and starts to break down over years.

Depending on what NHL strength that was used, the standard wall hydrolic lime used 3.5 NHL and goes upto 7.5 NHL which would be almost the tensile strength of concrete which I doubt was used.

 

[andyb1]

I am with earlier posts on this, I would leave well alone.

 

[Spare Tool]

Not really thread related but as Dave pointed out lime screed and render are meant to breath, as a point my local church had some builder re point one side of the church and they raked out all the lime and used sand and cement, after only 2 years the internal plaster is now falling off the walls on the side they repointed yet the side that was left in lime is fine..point is...leave well alone 😉

 

[Russell brown]

Not really thread related but as Dave pointed out lime screed and render are meant to breath, as a point my local church had some builder re point one side of the church and they raked out all the lime and used sand and cement, after only 2 years the internal plaster is now falling off the walls on the side they repointed yet the side that was left in lime is fine..point is...leave well alone 😉

If It was on a wall I'd agree but it's the floor and as far as I can gather the lime screed was to allow for movement. I've by far made any decisions I'm just trying to get all the relevant information to go back to the customer. Believe it or not for once Google is not my friend because there's sod all information one way or the other. I haven't gotten round to speaking with schluter but dural are confident that they matting is up to the job if a can find and slc suitable to use on lime. After that they said any flexible adhesive is ok. I just need to know if there's such a thing, plus cost will be a factor. As long as I can go back to the customer with the correct advice I'll be happy, don't want someone else jumping in saying it's fine to tile if it's not.

again thanks for everyone input it really is helping

Russ

 

[Spare Tool]

I'll guarantee someone will walk in there and say its "fine to tile" least you'll be able to sleep at night Russ

 

[Stocks Tiles]

So as it is that you've now already wasted a day trying to contact companies to ask the question, I imagine it's a small area and that it's now not going to really be a profitable job even if you done it? Customers are lovely, till something goes wrong and then you never advised them and knew nothing of any risks with something not working and spread a bad name about you. It really isn't worth the money or hassle for me personally, walk away crack on with other work and keep a clean name.

If not - Good luck!

 

[Stef]

What puzzles me is Dural saying as long as there's no more than 5mm movement over a 3m straight edge.
Correct me if I'm wrong but I'm sure that matting isn't designed for deflection.
I would be concerned about this info more than anything.
5mm lateral movement yes not 5mm deflection.