Plywood vs MDF - Loft Flooring

ste_bla · 26 Sep 2006 at 22:35

Putting down some flooring in the loft, due to lots on insulation I have put some xtra 2x2" planks Parallel down at 10" apart and then put bits of 12mm ply board on top, this has worked so far and easily holds my weight.

I have now run out of ply. So i went to wickes and had a look and its a fair bit of money and then i saw mdf lot cheaper.. so would mdf be as good? The guy at the store said it was a lot better as less flexing but surely cheaper=worse..

So ply or mdf fr flooring and also 9mm or 12mm thick?

Raymond Lin · 26 Sep 2006 at 22:39

MDF is REALLY strong, basically glued wood powder.

Dolph · 26 Sep 2006 at 22:41

The big problem with MDF is that it's rather unpleasant to work with much of the time, despite it's cheapness.

Some of the chemicals used to bind it are rather unpleasant, and they can leech out of the board. It also creates a large amount of dust which again isn't good for you. Mask etc is vital when working with it (not just when cutting it).

http://www.lalena.com/Audio/FAQ/MDF/

Personally I'd use plywood, it's a little more expensive but a lot less unpleasant.

VeNT · 26 Sep 2006 at 22:45

use plywood, treat it properly with preservatives etc and it will last AGES
MDF does flex less, but its more prone to snapping whereas plywood will flex but not brake (we did tests on this back at school ages ago) so whereas ply will just snap at xxx pressure, ply will take way more before it brakes

ste_bla · 26 Sep 2006 at 22:47

Hmm guess plywood then as it would need cutting..

shame its twice the price

..

VeNT · 26 Sep 2006 at 22:47

ste_bla said:
Hmm guess plywood then as it would need cutting..

shame its twice the price ..

for a reason

Mr Mag00 · 26 Sep 2006 at 22:51

Dolphs taken the words outta my mouth, it leaches awful chemicals into the air for years following installation, for that alone plywood for the win.

ste_bla · 26 Sep 2006 at 22:52

Actually realsied the price isnt so bad £7 per sq M vs £9 per sp M..

Usel · 26 Sep 2006 at 22:52

Also MDF is damn heavy and an 8ft x 4ft sheet while not to difficult to pick up is annoying to work with until you have it cut up into workable sizes.

ste_bla · 26 Sep 2006 at 22:59

Okay fair enough MDF sucks..

Now another question.. As the breams are 10" apart what thickness can i get away with.. for putting things on and me walking over (12-14st) at the moment the 12mm doesnt move at all so.. 9mm? 6mm? or just be on safe side and get 12?

Mr Joshua · 26 Sep 2006 at 23:01

How does the price of 3/4" chipboard compare?

I'm pretty sure that it's used quite extensively in flooring out lofts.

SCM · 26 Sep 2006 at 23:05

Mr Joshua said:
How does the price of 3/4" chipboard compare?

I'm pretty sure that it's used quite extensively in flooring out lofts.

I was about to say that myself as thats usually the flooring used.

As to cost think it was less than the prices quoted above by the OP for similar areas. Think my dad paid about £3-5 per just over 1m sq m a few months back.

SCM

Glaucus · 26 Sep 2006 at 23:08

MDf is the best for lofts, just buy big sheets and cover the entire floor. Just screw directly onto the joists. Cheap, strong and easy to work with. Much better than plywood. As long as you cut it using a mask, then health and safety is fine.

Combat squirrel · 26 Sep 2006 at 23:24

IM WORRIED NOW :eek:

Just put in a makeshift desk in my room made of MDF, bolted it to stairs banisters (they run round the area of the stairs, thus placing MDF ontop of them makes a 'table')

Strong as an ox, but it smelt aweful for 2 days after I soaked it in varnish, looks great,but I hope all these nasty chemicals didnt come out when I varnished it........man it smelt wrong as well,lol

danza · 26 Sep 2006 at 23:44

If there's any chance of it getting wet, don't use MDF if you're not going to treat it. Plywood is more flexible and I'd imagine the better material for laying across natural timber joists due to it's similar expansion characteristics.

Thickness? 12mm. 9mm seems too thin to me. I read that it's a good idea for a mininum of 19mm thk for joists 24" apart, and 16mm for 18" apart. 12mm defo imo.

Mr Joshua · 27 Sep 2006 at 00:16

Combat squirrel said:
Strong as an ox, but it smelt aweful for 2 days after I soaked it in varnish, looks great,but I hope all these nasty chemicals didnt come out when I varnished it........man it smelt wrong as well,lol

I wouldn't worry too much unless you're around the dust day in day out. A friend of mine (joiner by trade) is making a massive model railway using MDF that's been varnished for the baseboards.

i know nothing · 27 Sep 2006 at 03:14

Go to a builders merchants and ask for Sterling board. It's basically plywood but the glue used is waterproof, they use it for flat roof's etc. It has a coarser finish than plywood but would perfect for the job.

cheets64 · 27 Sep 2006 at 03:17

Kardean enuf said.

darreny · 27 Sep 2006 at 07:07

ste_bla said:
Hmm guess plywood then as it would need cutting..

shame its twice the price ..

it is more expensive for a reason, mdf is made from the waste from joinery and logging companys, and as there is gonna be a shortage of timber worldwide this year plywood is gonna get more expensive still (mainly due to china). a lot of joinery companys in the uk operate on break even for the products they make and the profit comes from the waste they sell on.