What size plywood should i use?

Hi, can anyone tell me what size plywood they would recommend fitting onto weyroc/chipboard subfloor flooring prior to secret nailing an 18mm solid wood flooring?
The other option i have is to use the adhesive backed underlay but just wanted to have two options.

Cheers in advance.

 

My own floor is fitted with just 4mm ply, primed, then I used Sika adhesive and also screwed it with tongue tights. Admittedly slightly over the top but hey, no creaks or squeaks 4 and a half years later I fitted mine on 45 degree with a perimeter plank, pain in the arse to be honest but looks pretty good when it's done.

 

Is the chipboard floated or fixed?

 

Fixed i believe mate, although the area was carpet when i went to look at it.

 

Sounds nice, did you have to put a bevel or anything on the ends cut into the perimeter?

 

Best to ask the manufacturer mate, I reckon you could screw down 9mm and nail. If the sub floors floated I wouldn't put solid over it.

 

Yup! 11 Bloody doorways all mitre cut then bevelled to match the factory bevell. I also biscuited the mitres to guarantee alignment.

 

personally minimum 9mm ply screwed down not nailed then prime and glue boards down rather than nailing

 

Would someone explain to me why a nailed installation would need ply at all when it's onto chipboard?

 

To create less horizontal movement.

 

If anything I would thought that would encourage natural movement with it breaking direct contact with the subfloor and allowing more flex to the cleats.

 

chipboard will not hold the cleats(secret nailing)properly over a period of time also the resins etc in the chipboard can cause problems over a period of time ,always ply over chipboard or you will regret it.

 

That makes sense.....cheers

 

The underside of the chipboard can blow out too much when you fire cleats into it.

 

chipboard is used quite simply due to being a CHEAP building material okay if floating over but for anything else always overply

 

also if it gets damp in anyway it turns to wheatabix

 

Okay.....but apart from all that why should you overlay chipboard with ply? All good answers that make sense

 

tHE ANSWERS ARE ALREADY STATED PREVIOUSLY.The other way is to rip out the chipboard.Weetabix should be brought to the table and not left on the floor.

 

the answers make sense cos theyre right ,the cleats wont hold to standard in chipboard so you MUST ply over.come on sandy.

 

It's ok Sandy, this Ayrshire lad picked up on the sarcasm in your last post