Rich writes: On 75 townhouse units, is it better to get bids or pay for time and materials on new siding and repair of dry rot? You can’t tell the extent of the dry rot until the siding is removed. I think the job will cost $300,000 to $400,000 to complete. The association members have many views. What do you advise?
Steve Bliss of BuildingAdvisor.com responds: It sounds like you have an unknown amount of decay in the sheathing and maybe the framing that will have to be repaired before replacing the siding. Some of the insulation may need to be replaced as well. There may also be damage to wood windows that will need replacement or repair.
In general, it will be very difficult to get a fixed bid on hidden damage. If you do get a fixed bid, it will probably be very high to cover the worst-case scenario. However, an open-ended time-and-materials bid could end up costing even more.
A middle ground is to get a fixed bid on the known portions of the job, such as siding installation, and a time-and-materials bid on the unknown portions. Base the time-and-materials portion of the bid on a fixed rate per square foot of damaged sheathing, framing, insulation, etc. That way you have some controls built into the process.
Also, nail down as much of the work beforehand base on a thorough inspection of the property, which on a job of this scope should be done by a third party well versed in exterior leakage and proper construction details. By removing a few pieces of siding, trim, or drywall on the interior, you should be able to get a good handle on the extent of the damage to the sheathing, framing, insulation, and windows and doors. There are consulting companies in many areas that focus on exterior leakage and water damage since, unfortunately, it is so common and the source of many repair jobs and lawsuits.
On a job of this scale, it might also be cost-effective to hire a construction manager (engineer, architect, or contractor) to write a specification, oversee the work, keep everyone honest, and make sure the repairs are done properly — so you don’t have to do this again in a few years. I’d recommend finding someone with extensive experience in exterior leakage inspection and repair.
The first step in repair work is to solve the leakage problem to keep water out of the walls. This involves proper installation of flashings and a water-resistive barrier (such as building paper or housewrap), with special attention to details around windows and doors. These details are often done wrong resulting in the type of problems you are now facing. You certainly don’t want to face them again in five to ten years. Good luck with your project.