Just wondering on your thoughts for marine ply I use nothing except 9 mill ply and feather other firms locally use 4 mm or 6 mm I feel that I am losing out on work by going for the belt and braces approach of 9mm ply and feather and coming in too expensive as a consequence I would rather not go back to a job in the long run. Or should i just ride the times and wait for the poop to hit the fan with other firms sub floor prep, i think that poor prep always comes back to bite ya!
6mm fine always renovation or 700 over though 9mm miles better but still prefer to reno or 700 that too, belt and braces myself mate
4, 6, 9, 12 mm etc. Its all about using the right thickness and type for the job. 4mm is fine if the subfloor allows. 12mm may be needed if the subfloor is bad. Interior, exterior, marine grade. Well that should be simple to answer. Where are you installing the plywood? are you installing interior, exterior or on a boat ? Please note, it dont matter how good a plywood you use and how good fixings are. If the subfloor wood moisture (teh floorboards) are not withing equilibrium of the plywood etc then you will be having issues no matter how thick a plywood you use. ply lines etc are caused by MC not being correct. Refer to a equilibrium chart to check the room RH and Temp to see if floorboards and plywood are acclimatised to each other. Many issues will be resolved. Just like a concrete subfloor, a wooden subfloor need to be checked to MC also !
and the customer always looks at you strange when you tell them the wood isn't acclimatised correctly, "well i was told 24-48 hours" no one seems to say minimum 24-48 hrs but could take much longer
Yep customers would love to have all that gear lying around for a couple of days to trip over and put a claim in.I always like to acclimatise myself with a cup of tea. Ply labour two trips you might as well screed!
just to note, you need to check if in equilibrium. Acclimatising is only needed if it is not. If its not then either the plywood has been stored in a wet or very dry area or there is a existing problem with the subfloor in the house. The reading you take when quoting will tell you this and 99% of the time the plywood in your warehouse will be ready to install without needing to be left on the job for days on end.
Seriously i cannot think of another trade? where BS is applied where you are working in a non BS environment? And as for moisture content on a wood floor as soon as you ply or screed you are creating a different environment and stopping air flow so British standards sail away again by creating a sealed environment. But its a heck of a great job!
Cheers Matt i am going to buy a warehouse for my ply next week as i am not sure of my suppliers environmental moisture content as the kettle is always on! But seriously in the real world you pick it up you fit it otherwise you would be out of a job!
You have lost me? The environment stays the same. The environment being just that, what is happening inside the property. So that being the RH and temp. Plywood is a wood product and reacts to moisture just like floorboards etc. If they are not matched to each other then they will start to move at different rates causing plylines for example showing a few months down the road even tho you used a skim coat. It is fairly simple to take readings and use a wood equilibrium chart to check all is ok. The real wood flooring chaps may understand more about what im talking about as it makes a massive difference to them if anything is out.
i will upload a wood equilibrium chart to the trade area which may help you understand what im talking about. Will have to wait untill im at office tho as dont have a copy here.
Cheers Matt i will get my name down for one of your courses this year probably just being paranoid about subfloor prep. What are your thoughts about when to ply and when not to ply after all ply takes more time than screed! time materials against labour? I have a job next month varnished floor boards nice and tight only a few gaps that can be sorted with caulk before screeding but how good is impervious primer over varnish? 3 day span for the job so its either ply feather wait pressure and lots of waiting or screed high temp and 3 days?
Cheers Matt it seems that i will have to update my standard reply of what do i know i am only a carpet fitter! I hope you got my satire on new builds and old sorry missus i will have to put a dpm down on your new build before i can prep your floor.
You should always plywood before using a fibre screed (yes i know some manufactures say you dont need to). So i guess that will answer your question ! Fibre screeds are more designed to take a dip out of a wooden subfloor or to flow between a wooden subfloor that turns into a concrete one. Your issue with the varnish is you will be relying on the strength of the varnish. A lot of them on the market now are effected by moisture so you may be asking for trouble when the moisture out the fibre screed starts to attack it. As for dpm in new build etc, yes it dont got down well with customers etc. However there are products out there that could have you applying a dpm and screeding on top in only 1 hour. Pleasant price to them also. So pleasant that you could absorb the cost of a dpm by changing what other products you may be using to cheaper and more efficient products. . Then we also for some types of lvt that could be installed with high moisture etc. Basically the floorskills courses go through all the different products / materials you could be using. We are not a manufactorier so our courses are different to saying " you have to do this" . Our saying is " you have these options and these different products that will do this " We go through most products out there, we use budget price items in the training that give proven results also so dont think we are only going to use expensive products. All our trainers are still active fitters so its real world training !
What about when you flexi over ply then, if you have both at equlibrium and then throw endless litres of water on it?
Plywood is very stable but will move if moisture is introduced over a period of time. Flexi screeds dry fast and the moisture is gone before the plywood starts to react to the moisture that was present when the compound was applied. Hence why a plywood is used and not something like hardboard that would absorb the moisture at much faster rate and start to move around / absorb moisture while the compound is setting
With flexi screeds the moisture is locked in at a molecular level i think that is why your hands are always sticky after use! Ooer missus and its a sod to get of your arm several hours after you have got in from work like picking a scab.(satisfying) But in our climate if ya carry ply into the job on a rainy day it all goes out the window to fubar.(Unless you protect the ply who does that?) I think that in my own mind regs and specs are over emphasised and it is all down to experience the correct product for the job and time over cost. I prefer fitting on high temp (messy) but great for getting the product tight, but pressure when the punter wants to use the area after the fit, In a perfect world we would all drop the ply,glue,product off the day before to acclimatise but in the real world the cost would be so high you would be out of work.
In the old days we used to nail hardboard down then use water on it to tighten it up,feeling old now!
