6mm backer boards on floor

[Charlie George]

Poster #10

Au contraire. Your mention of 5mm gaps for a floor deck and 3mm and 4mm gaps for a roof deck and frame sheathing is quite a bombshell after all these years of me following what I'd assumed to be standard industry practice and butting these boards together.

This major revelation needs further investigation and clarification, would you like to "expand" on this bombshell requirement?

3mm expansion gaps between boards is a well known requirement for ply and OSB roof decks and sheathing, or are you taking the pee

 

[mrrusty]

Your video FWIW also gets it wrong in a number of places

You mean the video provided by the plywood manufacturer about how to fit their own plywood? but I guess you know better than one of the UKs leading board suppliers....

 

[ree]

Poster20,
Stop ducking the questions I asked you - and the simple statements I made about your lack of knowledge.
Wheres your response?
Remember the dry rot mushroom rubbish you advised nonsense that could have cost the OP thousands - are you going to run away again? You fled, disappeared for months so I'm told?

OMG, are you saying that you place blind faith in a video because its been made by a well known name?
Have you ever heard of Thames Water or the massive company that still supplies death dealing insulation?
There are many more examples of big companies talking rubbish - one would think that you would know.

 

[robinbanks]

Problem is, when you don't install products as per the guidance set out by the technical department of the manufacturer, it typically voids any warranty on them.

Fairly binary choice; follow the instructions as per the well funded and researched design team of the manufacturer, or the instructions of a little known and, on occasion demonstrably incorrect, anonymous person on the internet?

My key point here is that the manufacturer offers a performance guarantee when I install their products as they say. What equivalent performance guarantee do you offer me if I install their products as you say?

 

[mrrusty]

follow the instructions as per the well funded and researched design team manufacturer

correct answer every time - and should be the answer more often promoted on the forums. Every single manufacturer of anything will provide installation instructions for their products, and that is always the correct method.

 

[stuart45]

I’ve laid a 18mm wbp ply bathroom floor

OP,
You lay the ply in a broken bond with 5mm expansion gaps at the abutment edges & , say, 2/3 mm gaps between ply sheets.

Although technically it's correct to leave a 2mm gap, it's already down now. Most chippies don't bother when doing floors, as provided the ply is acclimatised and well fixed the amount of expansion is relatively small. It's obviously a bit quicker to just butt joint it.
In the USA when doing roofs and walls it's a bit different as the climate is more extreme over there. Some of them still butt joint it and take a chance because of the fact on a long run you it throws them off with the rafter of stud spacing and you need to keep cutting.
However, technically an expansion joint is correct.

 

[Nige F]

Charlie George,
He's trolling,
He always resorts to trolling when challenged.

He's an aging man, a tattered coat upon a stick

and you are a dick on a stick

 

[stuart45]

In my early 20's I worked in the USA for a few years. In California it's not the best place for brickwork, so occasionally I did work with other trades. Back then the chippies were not using T&G for roofs or walls, so unless the framers allowed for 1/8inch gap it meant taking 3/8inch off every 3rd board to keep lined up. Maybe things have changed nowadays.

 

[stuart45]

Where's your post before my last one gone ree?

 

[Nige F]

removed by the mods ,probably - they do it a lot to little ree

 

[Nige F]

Poster20,
Stop ducking the questions I asked you - and the simple statements I made about your lack of knowledge.
Wheres your response?

How do you ask #20 when you're #18 ? response is one finger I guess.

 

[Nige F]

You've turned into Darth Vader

you should see the size of his light sabre

 

[23vc]

Cheers all. 6mm notched trowel ok for the addy onto the ply, or skim it thin?

 

[simplesteve]

6 mm Trowel is the man for the job. And do your fingers a favour by using Turbogold screws.

 

[phatboy]

Is screwing the backer board down with washers not enough, and adhesive is required, too?

I've heard mixed opinions over the years....