Wildly different quotes for laying travertine tiles...

[jono]

As the title says, I've had three massively different quotes for laying these tiles in my kitchen. Any advice would be appreciated.
The tiles I have bought are Hoppe Travertine Brush Chisel Edge unfilled tiles.
The space is about 19sq metres taking into account various intrusions like a breakfast bar, chimney breast, etc.
They wll be laid on floorboards. All three quotes included laying plywood first (one said 6mm, another 9mm).
First guy quoted £900 and said it would take about 7 days to complete.
Second guy quoted £1,300 and five days to complete using two people.
Third guy quoted £590 and two and a half days to complete.
All quotes included flexible adhesive, sealant and grout.
The tiles are varying shapes and sizes. I think each pack contains one large square (16in x 16in), one small square, one large rectangle, one small rectangle.
Which sounds the most realistically priced and timescale for laying?
These are north of England prices if that is relevant.
Many thanks
Jono

[ultimatehandyman]

I'm not sure about this, hopefully mudster will be on later. He has done this type of thing hundreds of times before and will know for sure

[Mudster]

Firstly, neither 6mm nor 9mm ply are rigid enough to accept stone. the minimum I would advise is 15mm if you have good solid floorboards.

An alternative and more suitable product would be Aquapanel, which 12mm thick, this should be glued and screwed to the floor. (Available from Wickes in 1200 x 900mm sheets at approx £12 sheet).

So you have 1 day to prepare the floor,
Two days of tiling, followed by sealant.
a day of grouting, leave overnight
come in to clean and reseal on day 5.

So five days work (maybe 4) if done correctly.

Materials will be somewhere between £350 and £450, for Aquapanel, rapidflex adhesives, screws, flexible grout, sealant and consumables.

Plus 4 or 5 days labour at whatever is reasonable locally.

In Surrey (which is where I'm based) that job would be £1500 - £2000, labour and materials, depending how complex the design is.

I'm concerned by the specs given to you by the quotes so far, I'd say non of them have any great experience of natural products and I'd search out someone else until you get a spec similar to that I've provided.

It's an expensive cock up if it's done wrong from the word go.

Also sealants....make sure they are not using HG Impregnator, it is too thick to seal dense products like Travertine correctly - they should be using Lithofin Stain Stop MN or an equivalent Fila product..

They should also be using white adhesive.