THE SINGLE BIGGEST CHALLENGE that we face in our facilities restoration effort is the poor and still-uncertain condition of the sanctuary’s long south wall. It is in bad shape. Fully defining the scope of the problem, and then fixing it, is the most urgent project (in terms of thereby avoiding an escalating cost of further delays). And it is the bottleneck on our way to refinishing (repainting) the interior of our sanctuary.
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| View from our neighbor’s parking lot |
This post sums up where we stand, after a recent report from a waterproofing consultant.
Diagnosis
This water intrusion dates back more than 25 years. Moisture continues to come in with every rainstorm. There are two causes:
• Construction defect: The concrete foundation was not waterproofed above grade before it was coated with stucco. This means that moisture travels through the foundation to the inside wall, dissolving salts along the way. The result is the accretion of white powder that has coated the inside surface of the lower part of the south wall. That powder won’t hurt anybody — but it keeps paint from sticking to the wall.
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| Efflorescence at bottom of wall in Row 14 |
• Deferred maintenance: Sun, rain, fog, and overnight condensation are all challenging for the integrity of wall surfaces such as stucco. Such wall surfaces need regular maintenance — to seal hairline cracks, repair holes, and (in older buildings) to keep it properly painted.
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| Missing stucco and cracks at base of post |
The upshot is that moisture has penetrated the walls regularly over a long period of time. As a result, there is untold damage inside the walls — quite possibly dry rot, termite damage (and active infestation), and perhaps mold.
Recently a large crack has opened up in the wall. In the black-and-white photo below, I have outlined it in blue. (Its stair-step shape probably follows the seams in the lath board that backs the wall plaster.)
We cannot know the extent of the problem, and therefore the cost to fix it, until we open up the walls — at least by making some representative test openings (“cuts”).
The extent of the degradation of the stucco itself still needs to be assessed. Contractors will not be able to give a firm price until such further testing is completed. We are preparing to pay someone to do the discovery testing.
Prescribed Treatment
The condition of this exterior wall is too deteriorated to be resolved by normal maintenance (i.e., filling cracks, patching holes, and repainting).
According to the consultant, there are two basic approaches to waterproofing this wall: (1) remove the existing stucco and start over (maybe $65K); or (2) apply a silicone-based coating system to the outside (maybe $40K). He recommends the second approach, which would have a 15-year lifetime if properly maintained.
“Everything needs to be sealed in that wall, from the top of the wall from the roof all the way down to the base.” From one end of the wall to the other. The thing about water intrusion is that if we eliminate most but not all pathways, we will still have water damage from the remaining one. I.e., ultimately the best use of funds would be to take a comprehensive approach, even though doing that would cost more up front. And that would be the only way to proceed with repainting the sanctuary interior anytime soon.
Prognosis
The situation is salveagable; the prospect of our achieving a watertight wall is very good if the proper measures are taken. That being said, the matter would not end there. Rather, the wall (like all external walls) will continue to need ongoing attention and maintenance, no matter what.
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