Dampproofing and Waterproofing - Be sure of the job specifications before pricing this subdivision - the difference in cost between waterproofing and dampproofing can be great. more info

Thermal Protection - Insulation and fireproofing products are measured by area, thickness, volume or R-value. Specifications may give only what the specified R-value should be in a certain situation. The estimator may need to choose the type of insulation to meet that R-value. more info

Steep Slope Roofing - Many roofing and siding products are bought and sold by the square. One square is equal to an area that measures 100 square feet. This simple change in unit of measure could create a large error if the estimator is not observant. more info

Membrane Roofing - Built-up or single-ply membrane roofing systems are made up of many products and installation trades - several different installation trades will need to work together on the roofing system. Inherent difficulties in the scheduling and coordination of various trades must be accounted for when estimating labor costs. more info

Joint Protection - To complete the weather-tight shell, the sealants and caukings must be estimated. The detailed drawings that are included as part of a set of architectural plans show typical locations for sealants and caukings. When caukings or sealants are shown at typical locations, this means the estimator must include them for all the locations where this detail is applicable. more info

Sheet Metal Work - Do not assume that all sheet metal items are “off-the-shelf” items. Gutters and downspouts as well as termite shields, gravel stops, expansion joints, and reglets may need to be shop-fabricated. Checking informational catalogs could save quite a tidy sum in extras.

Estimating the Specified System - Even though it may be less expensive to use a “sustainable substitute,” the system that is specified is the one that should be estimated. If you include as part of your estimate a non-specified system and get the job, you might be required to furnish the originally specified, more expensive roof system.