The Upper Side Chambers Project: Situation and Plans

OUR SANCTUARY BUILDING includes two long, narrow, enclosed chambers. They run high along the side walls between the ceiling and the roof. About 117’ long, their cross-section is approximately the shape of a triangle whose sides are each about 3’ long. 

The upper side chambers are underneath
the roof troughs that run along the long walls.

This post (originally published 8/1, now with 5 new photos and more info) lays out our plans for assessing the structural integrity and state of termite activity in these chambers, and for halting any such activity. The work of discovery and treatment is scheduled for August 15.…

The western end of these two chambers apparently connects to the area of roof joists above the Mezzanine ceiling. The eastern end of the southern one sits in the attic above the bimah — behind the fixed ladder to the roof opening — so that this chamber is potentially accessible from there by cutting through or removing the 2" x 6" planks that cover its end. (The northern chamber meanwhile runs all the way to the building’s eastern wall.) 

On 8/3, after Ruben cut a 6" x 8" hole in one plank, we taped a lamp to the end of a pole and inserted in as far as we could. Looking in toward the ocean, here's what we saw:

To my untrained eye, the tar paper (vapor barrier) and the wood appear to be in good condition overall. The slope of the lower surface is less steep at the edge than I expected, meaning that it would be easier than I had imagined for someone (small) to crawl through on hands and knees.

Within our limited field of vision, the one area where the wood looked questionable (mildewed? eaten?) was next to where a bundle of electrical conduit emerges from the attic:

Gaining Access to the Side Chambers

The present plan is for the roofers to cut 2 temporary access holes into each of the side chambers, while they are on the premises for annual roof maintenance. The size of these holes will be about 3’ x 4’. {Map updated 8/12.}

The most immediate result of these holes will be to (hopefully) confirm the presence of a layer of plywood between the upper roof membrane and the roof sheathing. This will establish whether or not the roof configuration meets the minimum life safety standard for earthquakes. And that, in turn, will determine the cost involved for replacing the roof membrane (either in summer 2023 or summer 2024).

Location of the Access Holes

Their proposed location is according to my best guess as to where access would be the most informative and useful, while being tied to building features that can be easily identified from the roof. 

(1) The southwestern hole is intended to be directly above evidence of past water intrusion: a large ceiling crack over the southwesternmost window. 

(Happily, this T-shaped crack seems to have been unchanged for more than a year.) Structural damage and termite activity seems especially likely in the vicinity of that crack.

(2) The southeastern hole is intended to be directly above the top edge of a large crack in the wall that seems to emanate from the roof. 

This crack (outlined in blue) continues on the other side of the southeasternmost window, until it reaches the foundation between the 4th and 5th rows of seats.

Here is the bigger picture (in black-and-white, for visibility):

That crack is itself above a wall area where termite activity was noticed nearly 20 years ago at the foundation (and left untreated until last year), and where water intrusion from grade level has been a longstanding problem. Unfortunately, it may be a sign of some problem with the structural wood there.

(3) The northwestern hole is near the adjacent building, where our neighbor found a thorough and apparently longstanding termite infestation in 2018 or so. My impression is that some portion of the boundary between the two buildings is made of wood — and thus termites could be active on our side of the boundary, as well. This hole will also hopefully afford a view of the otherwise inaccessible roof structure that is above the ceiling of the stairwell to the Mezzanine.

(4) The other northwestern hole is at the 2nd wall column on the north side, which is above a tie-rod connection that is showing an interior wall crack, indicating past water intrusion.

After the Access Holes Are Cut

Three parties are slated to investigate through the temporary holes, as follows:

1. A termite inspector from Higgins Termite will look for infestation. My expectation is that if termite activity is found, the termite company will provide an on-the-spot proposed treatment and a prompt estimate of its cost and — given prompt authorization to proceed — will provide same-day termiticide treatment of the infestation(s), so that the roofers can come back the next day to close up the holes.
2. A structural engineer from John A. Martin & Associates will check the structural integrity, so as to make recommendations for remediation if needed.
3. I will be on hand to learn what I can from the above parties.

Again, the twin goals of this project are to assess the condition (discovery) and to arrest termite activity. Although it seems likely that a need for some structural repair will also be identified, on balance it seems best to defer the actual replacement of structural wood until we have a clearer idea of what is needed and how much it will cost — and can get bids for the work and then set aside the necessary funds. (In the worst case, replacement of some portion of the curved vault beams might be indicated — which presumably would require considerable planning.) True, we would presumably need to cut open the roof again, but given a cost of $200 to open and close each hole, that seems like a relatively small price to pay.