DURING THIS SUMMER, it will be time to do major work on the roof of our historic sanctuary. Mishkon has saved up the funds to pay for this two-part project, and we have been preparing to carry it out.
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| A silicone “cool roof” recovering is applied in Torrance. |
Below the jump, this post describes what our preparation has accomplished: my understanding of the situation and of the options, and what our current plans are.…
Background
The present roof covering (i.e., the outer membrane whose surface is exposed to the elements and that keeps out the rain and provides fire protection) was installed 21 years ago. It is now at the end of its useful life and so reroofing is needed—either by replacing the covering altogether, or by recovering it with another layer.
In 2021, our board—recognizing that this day would be coming soon—authorized an expenditure of up to $85,000 to both replace the sanctuary roof covering and repair/replace compromised supporting structural wood. As of this writing, that 4-year-old spending limit should be sufficient to get the job done.
City terminology and regulations
In the Los Angeles building code, reroofing is the general term for either recovering or replacing an existing roof covering.
- Recovering (sometimes called restoration) = the process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.
- Replacing = the process of removing the existing roof covering, repairing any damaged substrate and installing a new covering.
According to several sources, recovering a roof does not require a building permit in L.A., whereas replacing it does.
Roof conditions
Of course we want to ensure a healthy structure underneath the roof deck. So in August 2022—as summarized HERE and detailed HERE—we opened voids underneath the roof that are normally inaccessible. We treated for termites therein but did not reinforce the structural wood that the termites had damaged, because that would have required opening up more areas on the roof, and we were not prepared (logistically or financially) to make repairs so promptly. Anyway, at the time I thought that the roofer could soon make those repairs efficiently during the upcoming renewal of the roof covering.
In addition, at the southwest corner of the roof is an area that has been inaccessible from below, as discussed HERE. Unfortunately, it has been the site both of ongoing water intrusion and of termite activity. We have treated for termites but do not know the extent of damage that they have caused. We ought to open it up from above, in order to inspect for possible repair and further treatment. (We don’t know what we will find; perhaps the need for major repair will come to light.) Until recently, I had thought that this could be done during the upcoming renewal of the roof covering.
However, it turns out that in general, roofers do not make structural repairs, because that requires a different kind of trade license. I.e., the above work needs to be completed before the covering is renewed if we engage a regular roofer to renew the covering. If we engage a general contractor that also does roofing, maybe they could do it all at one time.
Bids
For the repair and inspection tasks, we received 3 bids. It turned out that the general-contractor approach was considerably more expensive, so I hope that we can accomplish our goals via the 2-phase approach. (I’m trying to arrange for a water-intrusion expert to be on hand, to help with diagnosing. Furthermore, as part of this phase, I hope to ascertain whether the plywood deck’s nailing pattern meets the seismic code requirement, and whether we have seismic plates or parapet braces.) For this first phase, I expect to coordinate 3 vendors working as a team, at a total cost of about $8K.
For the reroofing task, we received 11 bids from 5 reputable roofing companies, one of which also holds a general contractor’s license. Between them, they offered 5 technical solutions, with different materials that each have their own pros and cons:
- Replacing with a modified bitumen covering
- Recovering with modified bitumen
- Recovering with silicone
- Recovering with elastomeric acrylic
- Recovering with spray polyurethane foam (SPF) + elastomeric acrylic
After evaluating and comparing these options, Fleming and I are favoring the recovering approach, rather than replacing. Happily, the roofers that have visited our roof believe that it is still in adequate condition for this. And our present roof has only one application of its covering, which is of the built-up type. Hence it is eligible for recovering.
Of the 4 recovering materials, the last three options listed are not only less expensive than modified bitumen (which is more traditional) but also offer the bright white finish known as a “cool roof.” Its properties reduce the surface temperature of the covering, which means that less heat would be transmitted into the building during the summertime. That would increase thermal comfort experienced by people inside the sanctuary and reduce electricity bills overall. In addition, the SPF option, unlike the others, provides insulation, which would add to those benefits.
We are still assessing which of those 3 materials will suit Mishkon’s needs the best, given their relative features and costs.
List of tasks
Phase 1
1. Open the covering and roof, to expose areas needing inspection and repair
2. Inspect for termites
3. Inspect for structural damage; identify where repairs are needed.
4. Repair structural wood
5. Treat for termites
6. Close/seal the
Phase 2
1. Prep the surface. Make general, annual-maintenance-type repairs to coping/flashing.
2. Apply a new covering.
3. Seal around openings and drains.
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