Soaked Chipboard and MDF in Loft Conversion

by **Entrigo** » Sun Sep 23, 2018 8:27 am

Hi,

New here. In the middle of a loft conversion and company has failed time and again to waterproof site, so currently having the 5th rain leak since it started. As a result, one of the roof chipboard panels is totally soaked through, and several of the MDF staircase steps have been subjected to a fair bit of water, as despite our best efforts we couldn't always place enough buckets/boxes under each leak.

Should we ask the chipboard to be replaced? I am not confident it won't just crumble at the slightest pressure (i.e. snow?) or with time, by itself.

What about the MDF stair? They will obviously say it's OK, as it would cost them too much to replace, but is it really OK? There is no swelling yet but it is starting to go soft, even in the parts which have not been soaked in the last couple of days.

Any advice will be much appreciated.

by **Sometimewoodworker** » Mon Sep 24, 2018 1:19 am

There is little question about the MDF even if it is Moisture Resistant MDF if it got enough water to go soft it needs replacing.

The chipboard you talk of almost certainly isn't chipboard but OSB Most of the time there is very little harm and the material doesn't loose strength or any of its integrity. but you will have to wait until it drys out to be sure, if dry it's the same thickness as the other panels it's probably OK.

by **Entrigo** » Mon Sep 24, 2018 8:14 am

You are right, as someone else in another forum also helped me see, it is OSB. Feeling better about that. Keeping an eye on the stairs now, waiting to see how they are when fully dry. Certainly don't want warped steps...

Thanks for the advice.

by **Sometimewoodworker** » Mon Sep 24, 2018 12:03 pm

Entrigo wrote:You are right, as someone else in another forum also helped me see, it is OSB. Feeling better about that. Keeping an eye on the stairs now, waiting to see how they are when fully dry. Certainly don't want warped steps...

Thanks for the advice.

If the MDF is slightly green then it's mr MDF and may be ok, if brown then it's probably regular MDF and will have to be replaced.

by **Entrigo** » Wed Sep 26, 2018 4:42 am

Mmm it looks brown to me, but it seems to have withstood the soakings, so maybe it is MR. Or we just got lucky. Or there is damage and we can't see it...

by **Sometimewoodworker** » Wed Sep 26, 2018 10:09 am

Entrigo wrote:Mmm it looks brown to me, but it seems to have withstood the soakings, so maybe it is MR. Or we just got lucky. Or there is damage and we can't see it...

If there is damage it would be impossible to miss it, so you may have one of the very few moisture resistant MDF's which is not tinted green.

Not soft, not swollen, then there is no damage .

by **Shem KSW** » Sun Oct 21, 2018 7:13 pm

As mentioned above the OSB should be ok, check the end grain for expansion if you can. If its just hit the flat surface it will be fine.

MDF, Hhmmm, maybe get another carpenter to check it for you?

Good luck