This article continues listing items that should be included in the preparation of both the preliminary cost estimate and the final bid for the complete residence. Also furnished is a guide on how to figure cost estimates for each of the items. (17) Garage doors- overhead wood garage door are in a category of their own- separate from other carpentry items. They are generally supplied and installed by subcontractors who specialize in this type of work. (18) Folding doors- folding doors, for estimating purposes, and interior fabric doors for closets. Here is a situation where you can phone a manufacturer for a price, giving him the specifications, the dimensions, and the number of doors required. (19) Most roofs in residential work are pitched roofs with asphalt shingles. For most flat roofs a built-up composition roofing is put down with insulation underneath it and usually with gravel on top. (20) Sheet metal- this item includes exterior gutters, down spouts, flashing at changes in roof pitches and possibly interior duct work originating from a bathroom. (21) Skydomes- These are plastic skydomes applicable to both flat and pitched roofs. Quotations on this item can be obtained from a supply house. (22) Metal siding is an item that the supplier will usually install. Determine the square feet of metal siding needed and obtain a unit price per square foot form a manufacturing concern. (23) Plastering- plastering in residential work consists mainly of either rock lath and plaster or metal lath and plaster, both on wood studs furnished by the carpenter contractor. A price can be obtained form a plastering contractor. (24) Drywall work- drywall has replaced plastering in many areas. In some areas drywall is dome by the carpenter contractor. (25) Acoustical tile- acoustical tile in residential work is usually limited to a game room or family room. For these small areas the work is generally done by the carpenter contractor. (26) Glazing- the glazing contractor will generally include the mirrors on doors and walls. A price for this work can be obtained from a subcontractor.