prep advice needed

[Spud]

I went to start a floor on Friday about 30m2, when we arrived 10mm warm up boards had been laid without been stuck to the sucfloor with adhesive and no washers were used just 40mm turbo gold screws , I told my lads to take out the screws and stick the boards down with spf rapid s1 setaflex while i drove over to Trimline to get the washers needed when returned i saw that the guys had stuck about half the warm up boards and i started putting the washers in ,i soon caught up with them and as they lifted some of the boards up i discovered the sub floor was tongue and groove particle/chipboard which had bee double layered over the joists, the joists were 400 apart but it was nailed not screwed , i told the lads to pack up and asked the home owner if he could get hold of the builder who claimed he had strengthened the floor to take tiles
my question is will a double layer of tongue and groove chipboard by strong enough to take tiles once it has been screwed to the joists every 200mm tiles arer 1200 x 600 porcel thin , at the moment I am thinking I will not tile it and am going to insist that the floor is prepared with a double layer of 18mm wbp ply wood
I would appreciate your thoughts please
Thanks Gary

 

[Qwerty]

Not good Gary. A bit of a predicament to say the least!
I would go down the ply route too if it was my job. Too big a "what if" otherwise

 

[peteablard]

Chances are it will be OK but I wouldn't want to guarantee it. Better to sort it now and walk away confident that you're not going to get a call in a week/month/year saying the tiles have cracked, Also I've not had a great deal of experience with those tiles, certainly not that size. You've probably got more experience with them than anyone on here, I think you know deep down what the right thing to do is.......

 

[Ken Bruty]

I think your first thought is correct Gary, I would be thinking the same too

 

[jonnyc]

gary i would relay the make up of double layered chipboard to supplier of warm up boarsd and see what they say about it.
you didnt mention what thickness chipboard was .
if it is screwed and cross bonded i would not forsee a problem but i never take a chance nowasdays.

 

[Spud]

up date of what happened there today, I met the builder there this morning who suggested I screw the flooring down and he insisted that the half we had covered with warm up boards had ample screws in it and was as solid as a rock he even jumped up and down on it and said if i wouldnt guarantee it he would , I said fine mate you wont mind if i remove the warm up boards then to double check that its screwed then , i then got a feather edge straight edge from the van and got my son to walk across the floor the straight edge started moving in a left to right motion as he took steps across the floor and dipped 4mm, i explained that there was far too much movement and we would be removing the warm up boards and the adhesive and give them back the floor as it was ,we took the first 4 boards up and tried to scrape back the rapid with blade scrapers and it was well and truly stuck and it took 2 of us an hour to scrape off 3 boards worth of adhesive so I had to drive home and get my concrete plane and dust extraction hoover , once we had this on site it was easy work and we were back to square one within an hour ,
total cost to me is 2 days wages for my son and 20 warm up boards ouch..... but its better than having a failed floor and my lesson is to double check the prep before I let my lads loose again oh yes the side of the floor which had ample screws in it had 11 screws in 12m2 and no nails any where to be seen
so the builder was very ready for me to take a hit on the floor so I now know he is a scum bag

 

[Pebbs]

Gary, one word of advice...disclaimer. Get the builder to sign it and then see if he changes his tune...I have a feeling he might do somehow.

Lynn

 

[Richard Edwards]

Gary

Lesson learnt - If in doubt, double check - Pebbs is right, most girls are I find. !!