Jump to content

Double board or layer of OSB?


Visti

Recommended Posts

23 minutes ago, Russdl said:

 

@Visti, I presume you’re referring to the highlighted 1200x800 10mm board? Unless I’ve read @Dreadnaught‘s table incorrectly your quote is way way more than 50p cheaper. It’s over £10 cheaper.

 

I’ve had a very similar quote price from Encon for the 12.5mm board, regardless of the size of board.

 

Correct, if you compare like for like in @Dreadnaught's table, it is more than £10 cheaper. But that supplier I've found overpriced by far. Thought the realistic 10 Vs 12.5mm £ comparison still being cheaper was more striking!

Link to comment
Share on other sites

1 hour ago, Visti said:

How many units you ordering? I'm at about 930 so volume may make a big difference.

 

Yes, I just chose the first supplier I found on the Internet (actually the second). Good to hear that I can probably get them cheaper from other suppliers. The intent was to start understanding relative prices of different size and thickness of boards. And of course, as I only used information from one supplier and one point in time, the results might be subject to one-off factors.

 

Don't know how many boards I will need yet (I have not yet done my version of your earlier splendid spreadsheet) but if I remember the size of your house correctly my guess is that I will need about half your number.

Edited by Dreadnaught
  • Like 1
Link to comment
Share on other sites

My situation is also different from yours @Visti if understood your intensions correctly, but I think closer to that of @Russdl. I intend to DIY the boarding of my house so choosing a board size that I can handle myself (or with one other) is paramount, whereas I think you are going to use a contractor team for yours.

 

Edited by Dreadnaught
Link to comment
Share on other sites

@Visti, @Russdl, will you both be choosing square edged boards (over tapered edge)? Can see the point of tapered edge myself. It seems to a product only for those transitioning from conventional drywalling and used to tapered edge.

 

And what did you think of using 10mm board vs 12.5 mm? I assume you are intending to use Fermacel everywhere, even on ceilings, in which case would have you ordered some 12.5 mm and some 10 mm?

 

And you won't be using a different board for the first layer where you will be doubling up for acoustic reasons, such as Gypwall Soundbloc?

Link to comment
Share on other sites

13 minutes ago, Dreadnaught said:

My situation is also different from yours @Visti if understood your intensions correctly, but I think closer to that of @Russdl. I intend to DIY the boarding of my house so choosing a board size that I can handle myself (or with one other) is paramount, whereas I think you are going to use a contractor team for yours.

 

 

The model assumes a contractor to compare like for like. We're actually DIYing it now as my sister wants a gig for a few months. Convenient!

 

I'll be going with square edge. Tapered just appears to be needed if integrated with other types of boards.

 

I was thinking of 12.5mm throughout with a single layer, even on ceilings, to keep the m2 installed low due to size

  • Thanks 1
Link to comment
Share on other sites

@Dreadnaught  Pretty much the same as @Visti expect I haven’t got a sister so the good lady had better be up for a bit of fun. 

 

The guy on the Fermacell helpline says exactly what Visti said regarding TE so basically of no use on a new build using Fermacell. 

 

Likewise I’m planning on 12.5 throughout as it’s ‘off the shelf’. 10mm would be a special order and they would only supply full pallet loads so there is the potential to end up with loads of excess 10mm boards if I got the sums wrong.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Reading through this lot the only thing I would add from a more hands on approach would be that if you use smaller boards make sure the team doing the jointing and finish knows this, if I turned up and you had used small sheets and there was double the joints it will cost you double the money to get it finished. 

I will be planning on using the biggest sheets I can find, if I can buy 4.8m in this country then that’s what I will use, I would rather pay for additional labour in fitting than having a joint every metre. 

  • Like 1
Link to comment
Share on other sites

13 hours ago, Russdl said:

 

It would seem that way. I've just spoken to Fermacell technical support (I'm going to have him on speed dial). He say's there is no need to use the  Powerpanel in a domestic situation. "You can use our standard panel with our waterproofing product or anyone else's waterproofing product, there all the same" he said.

 

 

He made it sound to be as straight forward as it looks, aimed at us DIY'ers. Jointstick on the factory edges, 5-7mm gap on cut edges and then filled later. FST for any painted finish. 

 

And he confirmed what we all know - it's very heavy.

 

That is exactly my experience. I used a 14" steel jointing spreader for the FST, and used 40m crown staples to fix the boards to either timber framing or battens on the walls. I struggled to get Fermacell filler so used standard Alabastine filler for the staple heads and gaps.

 

If you have reveals or returns to do then a cheap router with a laminate trim bit is ideal, cheap belt sander and extraction is always useful too !

  • Thanks 3
Link to comment
Share on other sites

On 26/11/2019 at 04:53, PeterW said:

If you have reveals or returns to do then a cheap router with a laminate trim bit is ideal, cheap belt sander and extraction is always useful too !

 

I don't quite follow you there @PeterW. Could you enlighten me on exactly what/why you used the router? What about cutouts for socket boxes? Did you router those or jigsaw or is there a better solution?

 

7 hours ago, Visti said:

Any of you considered stapeling the fermacell?

 

I hadn't. @PeterW says he has, perhaps he can give us pro's and con's. I guess it works out cheaper and quicker, but less flexible if you cock something up.

 

I'm about to plunge in to the board buying stage. Full boards would be ideal in theory, but in practice I could be doing this on my tod at times so '1 man boards' it will be. 1200 x 1200 seems an obvious answer, it's a straight forward 'half a board'. Any thoughts on the pro's and con's of the different size 'one man' boards, (1200 x 800, 1500 x 1000?)

 

Link to comment
Share on other sites

8 hours ago, Visti said:

Any of you considered stapeling the fermacell?

 

Me I suspect not.

Wisely or not, I am intending to use both (1) resilient bars in key areas; and (2) to use metal framing for all internal stud walls. I think both will necessitate screws.

Link to comment
Share on other sites

14 minutes ago, Dreadnaught said:

resilient bars in key areas

 

I'm planning on resilient bars as well which leads on to what I suspect is a very basic question. What should be done first? Ceilings or walls. The Fermacell help guy dude said 'whatever you want'. Is he right? Does anyone have any rules?

Link to comment
Share on other sites

1 minute ago, Russdl said:

What should be done first? Ceilings or walls.

 

My inexperienced assumption has been: (i) first fix plumbing and electrics (through the web joists); (ii) outer shell walls and ceilings complete; (ii) then MF framing for stud walls.

 

Happy to be corrected. 

Link to comment
Share on other sites

1 hour ago, Dreadnaught said:

 

My inexperienced assumption has been: (i) first fix plumbing and electrics (through the web joists); (ii) outer shell walls and ceilings complete; (ii) then MF framing for stud walls.

 

Happy to be corrected. 

 

When are you installing the windows and doors to make it weather tight?

Link to comment
Share on other sites

Sorry to keep banging on about Fermacell boards but here I go again...

 

Resilient Bars hang about 16mm from the ceiling and I plan on using 12.5mm Fermacell boards attached to them, that gives me 28.5mm from the board face to the joists above and the screw through the board shouldn’t touch the joists.

 

The smallest screw Fermacell supply for ceilings/walls is 30mm which is too long for what I plan to do but they do supply a 23mm screw for their flooring system.

 

Would that 23mm screw be suitable to attach the 12.5mm boards to resilient bars on the ceiling and walls, or will the whole lot come crashing down on me?

Link to comment
Share on other sites

1 hour ago, Russdl said:

Sorry to keep banging on about Fermacell boards but here I go again...

 

Resilient Bars hang about 16mm from the ceiling and I plan on using 12.5mm Fermacell boards attached to them, that gives me 28.5mm from the board face to the joists above and the screw through the board shouldn’t touch the joists.

 

The smallest screw Fermacell supply for ceilings/walls is 30mm which is too long for what I plan to do but they do supply a 23mm screw for their flooring system.

 

Would that 23mm screw be suitable to attach the 12.5mm boards to resilient bars on the ceiling and walls, or will the whole lot come crashing down on me?

Why are you putting fermacell on the ceiling. Are you planning on put some shelves up there?

You would be nuts to board a ceiling in half size sheets of fermacell. They will still be really heavy and all the joints will look crap. If you are doing it on your own hire or borrow a board lifter and use standard plasterboard 15mm thick or 2 sheets of 12mm. The guys I have seen who board out without using lifters tend to have no neck and look like power lifters. There is a reason for this.

Edited by Alex C
Link to comment
Share on other sites

19 minutes ago, Alex C said:

Why are you putting fermacell on the ceiling. Are you planning on put some shelves up there?

 

For sound proofing, plus I fancied keeping plasters away. And shelves one day...

 

21 minutes ago, Alex C said:

You would be nuts to board a ceiling in half size sheets of fermacell. They will still be really heavy and all the joints will look crap.

 

I’d not considered that. I was under the impression that using the Jointstick and finishing off with the FST it would be smooth as a babies bum but I’m well aware of the weight issue. Is it really not suitable for ceilings or is it my plan to use half size boards that is the main issue?

 

12 minutes ago, Russell griffiths said:

Do the resilient bars run parallel with the joists or at 90 degrees to them, if 90 degrees then it won’t matter if you use a longer screw as they will never touch the timber. 

 

Yet again Russ, thanks for pointing out the bleeding obvious that I hadn’t spotted! The bars run perpendicular to the joists and/or studs so you’re quite right - it shouldn’t be an issue.

 

Where would I be without you guys and gals. 

Link to comment
Share on other sites

You are always going to get a flatter finish by using the largest board size possible. Fermacell is crazy heavy and uses expensive screws that will be a nightmare to fix. 15mm large sheets of standard plasterboard or 2 sheets of 12.5 is how to get good sound insulation and use standard dry wall screws that will be a fraction of the price. Fixing boards to a ceiling without a board lifter will be the hardest workout you ever do. a 1200 x 1200 fermacell board weighs 21 kg. You cant lift that overhead and fix it on your own.

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...