Wet Walls / Condensation

[David Edenburn]

I am an inspector in Singapore (used to be a HI in Louisina). Here, all residential is apartments, all walls (including interior walls) are brick covered with 1/4" cement or plaster. No insulation. A common problem is when the occupant of one unit runs the A/C 24/7 making the party wall cold. The neighbor keeps the windows open (typical weather here is 90°F, 90% RH) and the A/C off. Result, condensation on the "cold" wall leading to mold, peeling paint, etc. Any suggestions? Nobody here wants a "hollow" wall (with insulation) and I can't get anyone to install EIFS on interior walls. Hope someone out there has dealt with this sort of thing before.
D. Edenburn

[Jim Luttrall]

Condensation is forming in the non-conditioned apartment, right?

Simple, tell them to close the windows and run a dehumidifier (called an air conditioner.)
Either that or insulate.
It would not take a lot of insulation, just an inch or so would raise the temperature of the wall above the dew point. You might get the person running the a/c to buy in on insulation as a cost savings.

Check out the Building Science website for a discussion and vapor barriers, dewpoints, etc.
Building Science Information (http://www.buildingscience.com/index_html)

[David Edenburn]

Thanks Jim for the reply. Of course that was the first thing I told them. The problem is telling people what they can or cannot do in their own property. I explained that they either had to close the windows, shoot the neighbor, or learn to like mold. Closing the windows is the most reasonable. Of course the builder is nervous since the owner may decide that it is all his fault. People paid over 3 million for these places and expect them to be perfect without any work on their part. Has anyone tried insulating paint, would that be adequate? I don't know what the "R-value" of those coatings would be.
David Edenburn

[John Carroll]

I would think that just the mention of "mold" would get somebodys attention pretty fast. If only the lawyers...

[Eric Barker]

It's like condensation on a glass of ice water. To control it you have only two choices - raise the temperature of the glass surface or remove the moisture in the air. If people don't want to do either than they live with it. End of story.

[Jim Luttrall]

Like Eric said, it is physics. You don't get away with breaking those laws without some consequences.
Insulating paints have to have snake oil in them...:D

[peter legeros]

Hi David,

Do you think two inch extruded polystyrene (R-10) (perm of .06) on the warm side of the wall with a mold resistant gyp bd interior face and an alkyd low perm paint creating a vapor barrier at the paint film surface would help?

Do you think you would even need the alkyd based paint if you seal the joints and the two inch extruded polystyrene acts as a vapor barrier?

[Daniel Leung]

The easy solution is: turn on your A/C too, just when people at home. You don't need to keep it 24/7, then no water condensate on walls.

[Jim Robinson]

$3 million and they would rather live with 90/90 then run the air conditioner? Sounds pretty crazy to me. Why even bother spending the money for the place?

[Craig Barr]

The thing I want to know is are you making any money over in Singapore?



I am an inspector in Singapore (used to be a HI in Louisina). Here, all residential is apartments, all walls (including interior walls) are brick covered with 1/4" cement or plaster. No insulation. A common problem is when the occupant of one unit runs the A/C 24/7 making the party wall cold. The neighbor keeps the windows open (typical weather here is 90°F, 90% RH) and the A/C off. Result, condensation on the "cold" wall leading to mold, peeling paint, etc. Any suggestions? Nobody here wants a "hollow" wall (with insulation) and I can't get anyone to install EIFS on interior walls. Hope someone out there has dealt with this sort of thing before.
D. Edenburn

[David Edenburn]

To Peter:

I would tell them to use insulation (that is what I would do in the US) except that here the fire code specifies that no "synthetic" material is to be allowed in construction. No foam (only rock wool) , no plastic pipes (all stainless steel), etc. Makes the fire department's job easier when all buildings are built entirely of brick or stone. In any case, I think the issue is moot. It has been several months now and I have not heard back from the owner. I assume they either started running the A/C (the prefered solution) or learned to love mold. For Craig, yes, the business here is doing very well. Average fee for an inspection is $70k. Of course we don't do many residences, it is all offices or factories. No recession in Asia.
David

[peter legeros]

Hi David, Interesting about the synthetics...thx for the update on the client.

If it comes back, it may be worth considering using rock wool insulation in lieu of foam, combined with a vapor impermeable paint on the gyp bd. warm side.

[Ken Amelin]

David,

Being that this is an apartment building in Singapore and the client owns the unit, I would assume that the deed or contract they hold is for the unit only and that the common areas are owned and managed by either the building owner or an association.

I would imagine that a "common" plumbing wall or building chase would be an Owner or Association issue and out of the unit owner's responsibility or control.

I would recommend that you advise your client to notify the owner or association of the problem and the potential danger of mold and mildew.
It would be their responsibilty to mitigate. And as responsible law abiding Singapore citizens I image they would.

[John Kogel]

Why don't they just hang up bamboo mats, floor to ceiling? If they go black, replace them or paint them.