I have a situation where solid masonry (8" of brick coated with cement and plaster) corridor walls are enclosed but not conditioned, they are open (windows with no glass) on one side. In our tropical climate, the morning dew literally runs down the walls. Inspection isn't the issue, we all see the problem. Aside from installing an insulated covering like EIFS (not feasible) all I can think of is a good coat of exterior paint to keep the water out of the brick. At this point the brick is so saturated that the existing paint is blistered and all kinds of things are growing on the wall surfaces. After I inspected and reported the problem the owner naturally wants a recommendation on what to do about it. Any help out there?

David Edenburn, Singapore

DE:

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Waterproof brick and masonry with DEFY masonry waterproofing products

__________________
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www.texasinspector.com

Thanks for the reply. I will pass your information along to the owner. In this case it is not so much a question of measuring or analyzing (although that is good info for the next time). When you have an actual stream running down a wall you don't need any instruments to see there is a problem. The cause is a cold brick wall in a 90% RH/90 degr. hot humid environment.
David Edenburn

Nothing short of an exterior insulation product will save that house.
Windows too.
While you're at it, my daughter lives on Ovid St. and needs a loan. How about slip over there and give her a hand.

JLMathis

I realize that an exterior insulation system would be the best long-term fix and if this was a simple house, I would recommend it. However it is a very large 5-story combination office and residential building (army barracks). A coat of paint is about as far as this is going to go. I can't find an Ovid Street here, sorry.
D. Edenburn

Why not hang bamboo curtains over those window holes, roll them up in the AM?

I agree, maybe put plastic over the windows to see if in fact it's the moist morning air condensing on the cool interior brick acting as a dehumidifier.

I have used a product in the past called Thorough Seal. sold at homedepot. made for sealing block walls. ? what sort of ventalation? any noticable?

It's true moisture might be entering through the block, but I would first eliminate the windows as a large source of the problem. There is also a product called Watertite that I have had good results with.

I assume that the brick is expose on the outside and plaster on the interior is that correct?

How old is the brick and what is the motar condition?

What is the top of the openings Brick , metal precast?

Pic would help

I agree with Stacey, A picture would help us have a more precise understanding? That will ellimenate the guess work!!!!

My first thought is why is the brick cold? That is what is causing the condensation in your humid environment. Is the brickwork possibly being chilled from the interior by air conditioning? Perhaps a layer of insulation on the interior would prove useful in keeping the brickwork closer in temperature to the exterior.

Another possibility would be that the brickwork, being very permeable, is sucking up all of that water, and in so doing, is setting itself up for evaporative chilling each night as the water in the brickwork is sucked back out as it's evaporated by night breezes. That's assuming of course that this building is in a generally windy environment. If this is the case, then you'll want to find a sealer that will still allow the brickwork to breathe while preventing water any chance of re-entry.

David,

I may have missed this in the posts above as I reviewed them, but further information is needed for clarification:
- The wall are structural brick, multiple wythes thick (basically two wythes thick) with plaster on the interior side of the exterior corridor walls which have openings (no windows) - right?
- The water is running down the inside, the outside, or both?
- The flooring is what material?
- The exterior wall along the inside of the corridor is of what construction and material?

From your description I think we can write off any effect from the interior as this is an exterior (not fully enclosed) corridor which is open to the weather.

As this is a multi-story building, is this affect occurring on all stories where this exterior open-to-the-weather corridor is?

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Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
www.AskCodeMan.com

Thanks for all the good ideas. Sorry, I was not allowed to take pictures (it is an army base). The walls are brick, about 12" thick with about 1/2" cement coating over the brick and about 1/8" of plaster over the cement. That is on both sides of the wall. The wall goes up 10' to a suspended ceiling (fiberboard tiles, badly damaged). Above the suspended ceiling the brick is exposed, no cement or plaster. The floors are concrete with ceramic tile. There is moisture damage on both sides of the wall but more severe on the "exterior" (corridor) side. Some of the interior rooms are air conditioned and some are not. However, the air conditioning is turned off at night and the windows opened. The problem exists on all floors but is less severe on the upper floors (probably due to better air flow). Data loggers confirm extreme variation in RH and temperature from day to night with RH from 80 to over 90%. My take is that the water cannot be eliminated so it can only be controlled by diverting it away from the masonry and utilities. "Water-proof" paint. The cool thermal mass (12" of brick) will always condense moisture with that level of humidity.
David Edenburn

The procedure of turning off the a/c at night and opeinig the windows is the downfall. Leave the windows closed and turn the a/c to the highest acceptable setting at night. The cyclical humidity swing are neither good for the building or the people. The economies of what they are doing when the a/c are not saving what they think they are.

Several design issues may be a play here. I would not rule several moisture sources. The first condensation due to AC on the interior rooms and the on-off cycle could be a issue but only on the conditioned walls. And if I understand the constuction as you describe it it is similar to many aparments, offices and hotels with a semi- enclosed exterior balcony. If this is correct then I would not expect any condensation issues on the out side of room walls. The driving force is on that wall for would be towards the room when the AC is on. And returning to neutral when turned Off. This should not affect the exterioro corroridor walls. I would also consider the condensation occuring becuase of thermal mass storage as a surface condition and as such it does not have a huge driving force. I the surface on both side of the wall is painted with a elastomeric paint that should stop any moisture penatration of moisture reaching dew point on the mansonary surface.

As i looked at you avg. rain fall I see it is in the 5-9" per month range. I did not find a rain driven rain index for the area but ,reguardless I would bet that a main issue is liquid moistue may be a issue.

The souce of liquid moisture may be from the condensation run-off and/or rain. both of which you are not going to control the exposure of the building elements in this case.

What you can control is the moistue entry into the building comopnets..

My choices of entry are several.

First you did not describe the deck or structure of the floor only that the covering is tile. I would assume that it is concrete.

You stated this a older building and I would make the assumption that the there is leaking at the floor both at the edges and in the field. If scuppers or floor drains are in place this is a very liklely area for leaks.

Sealing the edges with a trianglaer backer rod with a urathate caulk joint would be a start and coating the scupper areas/or floor drains. Also if for drain are present check the drain piping.
If by luck the concrete in the field is not cracked too much than a tile sealer may suffice. If not then a two part Coating (such as used on parking garages may be necessary.

My next area of concern would be the framed openings. Failing flashings. Terrcott. tile or what ever the top of the opening would be a likley moistue entry. Depending on what is there would vary my repair recommendations.

The next source of liquid moisture would be fom the stucco it self. Althouth you said this is a 12" brick wall it could be solid or with a 4" Gap in the middle. If the Stucco is less than a inch thich and a gap exist I would expect weeps. (Drainage system.) If the stucco is a 1" and then coated with a elastomer paint then no weeps would be necessary (Barrier System) This needs to be determined and then any repair made depending on the system type. Also after determining the the type of brick wall in place the lintels should be evaluate to determine if they play any role in the moistue entry.

As to the area above the ceiling tile

First I would clean with a CL-soap mixtue let dry then spray the area and top of the tile with a Timbor 15% soloution (Borax) for a residual treatment for cavity condensation. I would also vent the area.

Thats a start

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