Pre-fabricated trusses, or gang-nailed trusses, are commonly used for ceiling assemblies spanning 16 ft. to 46 ft. Roof trusses are made with flat parallel chords in lengths of 50 ft. to 150 ft. Truss rafters are sized depending on the shape and span of the roof framing.

To determine quantities of tile needed, measure the square footage, add 10 percent to compensate for bre akage, cuts andextras for future repairs, and then consult the manufacturer’s supply chart for quantity per 12.5 sq. ft. per carton, and for 11.5 sq. ft. per carton.

Typical considerations made when taking-off masonry include: installation method, materials, weather conditions, the need for
a scaffolding, reinforcement requirements, miscellaneous items and allowance for waste.

Gantt Charts are the basis for bar charts, which were originally used for production scheduling, but increasingly are used for
planning construction and recording it's progress. It's primary advantage is it's simplicity and ability to be understood by all
levels of management. Even though it is not the most efficient, it is the choice of most contractors in the residential/light commercial market.

knots, loose and plugged holes, splits and other defects. "A" has no defects; "B" is a solid face with tight knots and repairs allowed; "C" is a plugged veneer with splits limited to 1/8" wide and holes from 1/4" to 1/2" in size; D is the lowest grade with open spaces and no repair allowed.

Fees for electrical permits are typically assessed per job. Utility companies typically assess a hook-up charge to tie in a service or transformer per occurrence.

Basic types of roof systems include built-up, single-ply, metal and shingles and tile. Individual components of a built-up and single-ply systems are taken-off separately. Metal roofs are taken-off by the SF, with trim pieces taken-off by LF. For shingle and tile roof systems, underlayments are taken-off by the SF, and can be extended to the square. Special hip and ridge tiles or cap shingles are taken off by the LF, or in cases of clay tiles, by each. Drip edges and ridge vents are taken-off by the LF and can be converted to each.

Openings smaller than 4 SF are negligible. Ceilings are calculated by multiplying the length by width of the area to be covered. Walls and ceilings should be listed separately.

Blasted or drilled rock must be listed separately from other excavation. For estimation purposes, rock may exceed in-ground
volume by as much as 60 percent which should be accounted for. Rock type, proximity to existing structures, or drilling depth
required, special permits and the quantity of rock to be blasted or drilled all affect the contractor's estimation. It is advised that a rock blaster or drilling specialist be hired to perform this operation.

Piping connections may be grooved joint or threaded. Fittings are taken-off by each, and classified by type (elbow, tee, reducer, etc.), and method of connection and material composition (steel,PVC, iron, etc.). Valves and special appurtenances (gauges, flanges, etc.) are take-off by each, and listed according to type, manufacturer, model, size and application. Sprinkler heads and discharge nozzles are taken-off by each, and listed according to type (pendent, sidewall, etc.), temperature range, manufacturer and model.

Concrete unit masonry are commonly referred to as CMU. CMU is widely used in commercial and industrial building applications. It is also used in residential construction as foundation material.

Standard (wood strip) flooring is manufactured in various thicknesses and is nailed or installed with adhesives according to the manufacturer's recommendations. Parquet is generally installed with adhesives. Hardwood plank that is impregnated with acrylic and pre-finished laminate and hardwood veneer are installed with adhesives as well.

When pouring concrete in cold weather, it is important to keep the concrete above freezing for the first few days, and is usually covered with plastic to contain heat and moisture from the mixture in order to encourage curing.

To express a decimal fraction as a common fraction, the number after the decimal point is written as the numerator of the common fraction, and the denominator is written as a 1 followed by as many zeros as there are digits to the right of the decimal point.

Additional considerations include chemicals added to the mix (drying agents) and type and size of aggregate used, as well as
lightweight aggregates used to reduce weight per CY. Hot water requirement, ready-mixed concrete, and stiffness (ease of pour) also affect cost estimation.

Drafting a schedule is necessary to determine project progress, and tentative task and project completions.

Material imported or hauled away from a building site in excess of 50 cu. yd. loads, must be ’permitted’ to be sure of proper supplier provisions as well as the availability of proper disposal sites and/ or methods of disposal of sometimes contaminated materials.

Two major types of scales are the architect's scale, and the engineer's scale. The architect's scale used on floor plans is %
scale where %" = T or % scale where 7e" = 1’. The engineer's scale is in increments of 10, 20, 30, 40 and 50, where, for
example, the 10 scale represents 10 feet per inch, the 20 scale represents 20 feet per inch, and so on.

Simple residential building plans require a plot or site plan indicating the proposed building vicinity, lot and building
dimensions, existing and proposed buildings, etc. Other plans included in the building plans are the floor plan, exterior elevations, cut-away plan, construction details, materials lists and specifications, and specialty items.

Modifications, revisions or additional clarifications for any reason, added to the contract during the bidding period, after the
drawings are issued, are addenda. They can only be issued by the designer, must be in writing, and become part of the contract document.

The take-off must list the quantity of each length of joist separately and extend total LF for that length.; Length = span of joist + required bearing at each end. Example: Length of the floor frame = 32'-0"; 32’ 0" = 24 joists +1 end joist = 25 joists, 16" O.C.,1.33

Field tile for ceramic and quarry tile applications are taken-off by SF. Special tiles are taken-off by each. Ceramic and quarry trim pieces are taken-off by LF.

Working drawings must comply with all regulatory agency requirements and include all of the detail that the contractor will need to prepare an estimate.

Water stain is the most penetrating of all stains, especially when used on base wood. Water-soluble powder is made from aniline dyes. Best results are obtained when the powder is added to very warm water and dissolved completely. Spirit stains are also aniline dyes, but are mixed with alcohol and are difficult to use since they dry quickly and possibly unevenly. Pigment oil stains are powders and are soluble in naphtha or turpentine. Pigments are made from various oxides and silicates mixtures.

Soil stability determines the angle of repose. The more cohesive the soil, the steeper the angle of repose. Non-cohesive soils
such as sand and gravel, require more shallow slopes and may further require shoring, or a trench box, to mitigate a potential
cave-in. OSHA has specific requirements for trenches and slope ratios based on soil stability type, trench depth and duration of openness.

Construction details on plan drawings may also be scaled at 1" =1'-0". Elevation plans are scaled at 1/4: = 1"-0". Plot plans are
scaled at either 1/16" = 1'10" or 1/8" = 1'-0’. Site plans are scaled at 1/32" = 1'-0".

Other methods for take-off of formwork for walls are by the LF where contact area is less critical than the size of the form panels
used. LF are most often used by contractors. Formwork varies in size and composition but is often constructed from a wood
facing applied over a steel or wood frame. Quantities of formwork must include the erection and bracing of forms until concrete is hardened, and stripping and cleaning of forms when work is completed. These tasks should be priced separately.

Buildings which require mechanical plans and specifications have an area of 15,000 sq, ft. or more, which includes the
basement. Buildings with environmental heating or absorption cooling systems with a BTU input capacity greater than 350,000 also require mechanical plans and specifications.

The quantity for take-off is the computation of the SF area. A standard waste factor of 3-5 percent should be added.

Waste system pipes which provide adequate flow of wastes, protect against cross-connection and keep noxious fumes from escaping may be cast iron, copper, brass, galvanized steel, or in buildings up to 3 stories in height, ABS or PVC-DWV plastic pipe.