Builder recommends I replace all joists before tiling!

[peterparker]

Hi there, fantastic forum by the way guys!

I've just had a large kitchen/diner extension built. It is made up of three parts

1) The original Edwardian house with suspended wooden floor

2) An extension built about 7 years ago with solid floor

3) Extension built now with suspended timber floor


I had the original suspended floor tiled with limestone tiles about 7 years ago and they started to crack after a year or so. The guy who laid the tiles said he was very worried about the choice of tiles and movement of the floor but I ignored him(!) and he did his best and used latex etc. But crack they did, big time. Never came loose, just long cracks running from tile to tile.

Anyway, my present builder says the same thing might happen in this section ( ie part 3) again and says the joists are very thin (? 4x2?) and not up to the job. He wants to rip them all out and replace with 8x2, extra noggins etc.

I like to do things properly but this is going to cost me £3500 which I hadn't budgeted for.

Are there any cheaper options to stop the floor deflecting?

Or did the tiles crack because they are limestone and therefore very soft, and therefore porcelain would be ok?

Thanks for your help

 

[White Room]

How big was the extension....

 

[Ajax123]

4x2 solid timber joists (which in metric is a bit smaller i.e 100mm x 45mm usually) ?? Eek! What sort of spans were they and at what distance apart.... I would anticipate no more than 1.4 to 1.6m clear spans at 400mm centres and that would be based on normal domestic loading screen I.e. Dead load of 1.5kN/m2

 

[Time's Ran Out]

Bet he didn't use Ditra with the stone either!

 

[Stef]

As said above, how far do these 4x2 joists span?
A cheaper option than recommended will probably cost you more money in the long run..

 

[Chalker]

If you have no rooms under the suspended floor, and if there is not too much build up. You could make it into a solid floor?

 

[peterparker]

Thanks for the replies.

The entire width of that part of the room is about 5.5m. What I don't know as yet is at what intervals the joists are supported. I'll know that soon when they uncover some more of it.