Moisture resistant MDF

[RogerS]

At least that's what I thought I'd ordered but never ever having actually seen the stuff I was a bit surprised to find it looking like a liquorice allsort...what looks like normal MDF on the two outside faces and ssome sort of green stuff in the middle.

My first thought would be that the moisture resistant part should be on the outside but I'm probably missing something here.

Roger

 

[jasonB]

Depends on the make, some are green all the way through some have a coarser green core and "normal" colour outer surface. The green can also fade with exposure to light. The main thing is that it has got some green colouring so you know that its MR, the green is only a dye for identification purposed.

Jason

 

[wizer]

i have some 'class 1' mdf which has fire resistent properties and it's core is red.

 

[jasonB]

And to complete the set Medite exterior has a grey core.

Jason

 

[DaveL]

Well I have learnt some new from this thread today, obviously not time to get in me box yet. \/

 

[RogerS]

Thanks for putting my mind at rest, guys.

Roger

 

[jonny boy]

Hi,

I use a lot of the M/R mdf for bar fitting, the sort we use has a brown formica type surface on both sides it has the green core and even though it is moisture resistant, it has been known to blow apart if in contact with area's which are very wet.

cheers,
jonny.

 

[jasonB]

The MR is really only for use in areas of high humidity, if it is likely to get wet then Exterior grade should be used but this should be sealed / painted on both sides & all exposed edges.

I use MR almost exclusively as I find the cut or moulded edges are a lot dencer and take a finish better.

Jason

 

[tim]

Jason

Do you find it heavier in general?

Cheers

T

 

[jasonB]

Its no heavier than a decent quality standard MDF like Medite or Caber but is a lot less "fluffy" and maybe more denser than the cheaper boards from builders merchants and the sheds. I just find it takes a routed edge much better and you get less plecking after the first coat of paint.

If I have a job where weight is an issue then the "Superlight" & "Ultralight"
boards come into there own as they are about 2/3rd the weight of standard MDF but only good if the edges are not exposed as the core is very "fluffy"

Jason

 

[Mike B]

JasonB

At the risk of appearing totally ignorant, if you get a minute please would you expand a little on the range of MDF available??

I had heard of a lighter weight grade (but never actually seen any nor realised that there were several grades) and have no idea what "Medite" or "Caber" is, nor that red/green/grey cored versions existed!!

Where have I been...

Cheers
Mike

 

[jasonB]

Medite & Caber are two MDF manufacturers

Standard Grade approx 750kg/m3
High Density (HD) approx 960kg/m3
Moisture Resistant (MR or 313) Green core or solid green approx 750kg/m3
Fire resistant (FR) red/pink core 750kg/m3
Exterior grey core 750kg/m3
Zero Formaldehyde (ZF) 750kg/m3
Floor Quality (FQ) 850kg/m3 - used to make laminate flooring

Lightweight 610kg/m3
Super/ultralight 500kg/m3
White painted - carcase backs
Melamine faced
Laminate faced
Veneered

And there are probably one or two more out there

Jason

 

[Mike B]

Thanks Jason