concrete floor question

[thetyreman]

I currently have some of my wood stacked up on a concrete floor against the back wall of the garage,

from what I've heard this is bad because moisture can get into the wood,

so I was thinking of making something very simple perhaps a damp proof membrane and then hardboard on top like a raised plinth , would this improve things? and how much should I worry about this? I am wondering if it's a waste of time,

attached are some pictures to show you

regards, Ben.

 

[Paul200]

Not sure if it applies here but it sounds a similar situation. when we bought our house it had vinyl flooring laid directly onto a concrete floor in the utility room. Couldn't work out why it always smelled damp (it was a new extension, built correctly with a dpm and 100mm insulation) - and then we lifted the vinyl! It was like a swimming pool underneath. I've since worked out that condensation was occurring between the cold floor and the warm vinyl.

Since we removed the vinyl and let the floor dry out there's been no recurrence. Still not sure why an insulated floor is so cold (the original concrete floor in the older part of the house is laid directly onto the soil and not a sign of damp!) but we will be laying tiles on it so hopefully won't be a problem.

Sorry - I digress - my answer would be to simply stack your timber on a pallet or some other raised platform but not to use a membrane as it's likely to make things worse!

Paul

 

[Orraloon]

I agree with Paul. Raise it off the floor and get some air under it.
Regards
John

 

[MikeG.]

Not sure if it applies here but it sounds a similar situation. when we bought our house it had vinyl flooring laid directly onto a concrete floor in the utility room. Couldn't work out why it always smelled damp (it was a new extension, built correctly with a dpm and 100mm insulation) - and then we lifted the vinyl! It was like a swimming pool underneath. I've since worked out that condensation was occurring between the cold floor and the warm vinyl...........

No, I doubt very much that this is what was happening. If the vinyl was warm, so was the air above it (otherwise there is no explanation for the vinyl being warm). If you removed an area of vinyl the warm air would have been in contact with the cold surface of the concrete and condensed in exactly the same way. In other words, the vinyl, under your theory, makes zero difference. Besides, water vapour is held by air, and if there was no (or minimal) air between the vinyl and the concrete then there was no air-borne source for the moisture. This is before we get into the thermal mass issues, which would suggest that the vinyl is going to be at the temperature of the concrete, not the air, and that airborne moisture condensing would have done so on the top, not the underside of the vinyl.

I think what was happening was that the vinyl was laid too soon on a newly poured floor, and trapped some of the construction moisture. This had literally nowhere to go, so may have sat there for months or years. Removing the vinyl, allowing the floor to dry fully, then replacing the vinyl would in my view have solved the problem.

 

[Lazurus]

Go for a pallet cheap and effective, if there are any problems it is easy to replace in the future.

 

[Paul200]

No, I doubt very much that this is what was happening. If the vinyl was warm, so was the air above it (otherwise there is no explanation for the vinyl being warm). If you removed an area of vinyl the warm air would have been in contact with the cold surface of the concrete and condensed in exactly the same way. In other words, the vinyl, under your theory, makes zero difference. Besides, water vapour is held by air, and if there was no (or minimal) air between the vinyl and the concrete then there was no air-borne source for the moisture. This is before we get into the thermal mass issues, which would suggest that the vinyl is going to be at the temperature of the concrete, not the air, and that airborne moisture condensing would have done so on the top, not the underside of the vinyl.

I think what was happening was that the vinyl was laid too soon on a newly poured floor, and trapped some of the construction moisture. This had literally nowhere to go, so may have sat there for months or years. Removing the vinyl, allowing the floor to dry fully, then replacing the vinyl would in my view have solved the problem.

I did wonder about that too Mike, but I couldn't believe the moisture would hang about that long. Then again, the vinyl was very well fitted. Even though I thought I knew the answer it's always been a question in the back of my mind so thank you for clearing that up for me.

Paul