Memorization Information

MEMORIZATION INFORMATION

About This Chapter

The information presented in this chapter is taken directly from the remaining 10 reference materials that you will not have with you in the PSI Exam Center. Therefore, you will have to memorize this information.

When the faculty at The Construction Institute receives feedback from students who have taken the exam concerning new questions, we research the question in the appropriate reference book and gather the information required to answer that particular question. It is precisely that type of information that follows in this chapter.

The following ten reference materials have been used to provide the memorization information:

ADMINISTRATIVE CODE — NC State Building Code: Administrative Code & Policies, 2018. Laws and Regulations Applicable to General Contracting in the State of NC.

SITEWORK — Pipe and Excavation Contracting; NC Administrative Code, Title 15A, Chapter 4, Sedimentation Control; NC General Statutes Chapter 113A, Article 4, Sedimentation Pollution Control Act of 1973.

CONCRETE & REINFORCEMENT — The Contractor's Guide to Quality Concrete Construction.

MASONRY — Modern Masonry.

CARPENTRY — Carpentry & Building Construction; BSCI: Guide to Good Practice for Handling, Installing, Restraining, and Bracing of Metal Plate Connected Wood Trusses.

ROOFING — Roofing Construction & Estimating.

This reference book is permitted to be taken into the exam center; however, there are often no questions from this book. We do not recommend purchasing this reference book. If you already have this reference book, and decide to take it with you when you test, you should highlight from the following material.

Section 107 Inspections

107.1 General. The inspection department shall perform the following inspections: Footing inspection; Under-Slab inspection, as appropriate; Foundation inspection, wood frame construction; Rough-in inspection; Building framing; Insulation inspection; Fire protection inspection; and Final inspection.

107.1.1 Footing Inspection. Footing inspections shall be made after the trenches are excavated, all grade stakes are installed, all reinforcing steel and supports are in place and tied, and all necessary forms are in place and braced and before any concrete is placed.

107.1.2 Under-slab inspection. Under-slab inspections, as appropriate, shall be made after all materials and equipment to be concealed by the concrete slab are completed.

107.1.3 Foundation inspection, crawl space. Foundation and crawl space inspections shall be made after all foundation supports are installed.

107.1.4 Rough-in inspection. Rough-in inspections shall be made when all building framing and parts of the electrical, plumbing, fire protection, or heating-ventilation or cooling system that will be hidden from view in the finished building have been placed but before any wall, ceiling finish or building insulation is installed.

107.1.5 Building framing inspection. Framing inspections shall be made after the roof (excluding permanent roof covering), wall ceiling and floor framing is complete with appropriate blocking, bracing and firestopping in place. The following items must be in place and visible for inspection:

1. Pipes; 2. Chimneys and vents; 3. Flashing for roofs and chimneys; 4. Insulation baffles;

5. All lintels that are required to be bolted to the framing for support shall not be covered by any exterior or interior wall or ceiling finish material before approval. Work may continue without approval for lintels supported on masonry or concrete.

107.1.6 Insulation inspection. Insulation inspections shall be made after an approved building framing and rough-in inspection and after the permanent roof covering is installed, with all insulation and vapor retarders in place, but before any wall or ceiling covering is applied.

107.1.7 Fire protection inspection. Fire protection inspections shall be made in all buildings where any material is used for fire protection purposes. The permit holder or his agent shall notify the inspection department after all fire protection materials are in place. Fire protection materials shall not be concealed until inspected and approved by the code enforcement official.

107.1.8 Final Inspection. Final inspections shall be made for each trade after completion of the work authorized under the technical codes.

Excavation & Grading

Site Preparation: Hub and Reference Stakes

A hub is a small stake driven into the ground to identify a reference point.

A reference or information stake will be driven in the vicinity of the hub and will identify the hub's elevation and situation in relation to the pipeline. The distance shown on the reference stake is a horizontal measurement of the distance from the hub to "centerline" of the cut or fill. (Also called the "Offset")

Slope as a Percent

Vertical rise is expressed in units of rise or fall, compared to a horizontal distance of 100 units. I.e. a 5% slope will rise/fall 5 feet vertically in a horizontal distance of 100 feet.

A 45° angle is a 100% slope. If the vertical rise/fall is equal to the horizontal distance, the slope is 100%.

To calculate slope as a percent, divide the vertical rise/fall by the horizontal distance (or run).

Slope = Rise ÷ Run

Dealing with Rock

Igneous rock is formed from molten magma and is the hardest type of rock to excavate or rip.

Sedimentary rock is formed from sediments that were compressed by water and overlying layers and is the easiest rock to excavate or rip.

Working in Groundwater

The level of the underground water is known as the water table. The water table varies in depth from season to season. A WellPoint system can be used to lower the groundwater table in bad groundwater conditions. Groundwater causes unstable soil that's dangerous to work in & impossible to use as backfill.

Soil Compaction

Soil Structure — the right amount of moisture for compaction to maximum density is called the optimum moisture content.

Determining Soil Density

Three methods of determining soil density are the Proctor test (Standard or Modified), the sand cone test and the nuclear density method.

A nuclear density test is advantageous because soil samples do not have to be removed from the site to perform the test. It is, therefore, a "Non-Destructive" test. Proctor & Sand Cone tests are "Destructive."

Earth Moving Equipment and Procedures

Push Scrapers

Push scrapers are used on extremely large earth moving projects.

A self-loading scraper (commonly referred to as a "Pan") will be more productive in hard or muddy soil when assisted by a dozer pushing on the push blocks to the rear of the bowl.

Downgrade Dozing

A positive grade is an uphill slope. A negative grade is a downhill slope. The blade load capacity of a dozer doubles if the load is pushed down a negative 40 percent grade. I.e. a dozer with a blade load capacity of 2.5 CY can push 5 CY yards down a negative 40% grade.

A positive grade has a negative effect on dozer production. When a dozer has to push its blade load up a 40 percent slope, the blade capacity is cut in half. I.e. The dozer with a blade load capacity of 2.5 CY can push 1.25 CY up a positive 40% slope.

Grade / Blade Capacity / Production / Production Time — Positive 40%: Cut in Half / Cut in Half / Doubles. Negative 40%: Doubles / Doubles / Cut in Half.

Angle Dozing

Blade angling increases the versatility of the machine. An angled blade ("A" blade) dozer can side cast material in a "Windrow" and position it at 90 degrees to the line of travel. The straight blade ("S" blade) ("Bull-dozer") allows the material to spill to each side of the blade and is not as efficient as the "A" blade dozer in moving material.

Traffic Control

The preferred method of traffic control for a lane closure at night is the use of reflective barrels.

Earthwork Calculations

Length (in feet) x Width (in feet) x Depth (in feet) = Cubic Feet

Then divide by 27 Cubic Feet per Cubic Yard = Cubic Yards of Earth

To do this with a regular calculator you will first have to convert inches to feet, before working the above formula. For a footing excavation that will be 120 feet in length and 16 inches wide and 8 inches deep, you will first have to convert 16 inches and 8 inches to feet by dividing each of them by 12. Doing this you will get 1.33 feet for the 16 inches and .67 feet for the 8 inches.

You can then multiply 120 x 1.33 x .67 to come up with 106.93 cubic feet. You then have to divide the 106.93 cubic feet by 27 to arrive at the correct answer of 3.96 cubic yards.

Construction calculators are permitted for use in the exam. They make the calculation noted above a lot less complicated.

Sedimentation & Erosion Control

General

Based upon the "Sedimentation Pollution Control Act of 1973" which applies to sedimentation caused by erosion or depositing of soil principally from construction sites and road maintenance. Does not apply to agricultural activities, forestry or mining or emergency activities essential to protect human life. (Note: The typical question asks, "Which of the following would be covered by the act? or would not be covered?")

Sedimentation occurs when flowing water slows down enough to allow suspended soil particles to settle. (Note: This is the most frequently asked question.)

15A NCAC 04B.0108 Design and Performance Standard

Erosion control measures shall be planned, designed, and constructed to provide protection from the run off of that 10-year storm that produces the maximum peak rate of run off.

15A NCAC 04B.0118 Approval of Plans

(a) Persons conducting land-disturbing activity on a tract which covers one or more acres shall file three copies of the erosion and sedimentation control plan with the local government having jurisdiction or with the Commission if no local government has jurisdiction, at least 30 days prior to beginning such activity and shall keep another copy of the plan on file at the job site.

(c) Erosion and sedimentation control plans may be disapproved unless they include an authorized statement of financial responsibility and ownership. This statement shall be signed by the person financially responsible for the land-disturbing activity or his attorney in fact. (Note: The person financially responsible for the site development is responsible for the sedimentation and erosion control. This is the 2nd most frequently asked question.)

15A NCAC 04B.0120 Inspections and Investigations

(a) Inspection of sites shall be carried out by the staff of the Department of Environment, Health and Natural Resources or other qualified persons authorized by the Commission or Department of Environment, Health and Natural Resources as necessary to carry out its duties under the Act.

15A NCAC 04B.0125 Buffer Zone Requirements

(a) Unless otherwise provided, the width of a buffer zone is measured from the edge of the water to the nearest edge of the disturbed area, with the 25 percent of the strip nearer the land-disturbing activity containing natural or artificial means of confining visible siltation.

(b) The 25-foot minimum width for an undisturbed buffer zone adjacent to designated trout waters shall be measured horizontally from the top of the bank. (Note: Waters that have been classified as trout waters shall have an undisturbed buffer zone that is a minimum of 25 feet wide or of sufficient width to confine visible siltation within the 25% of the buffer zone nearest the land-disturbing activity, whichever is greater.)

Methods

Diversion dikes for perimeter protection must be at least 2 feet across at the top, and 18" high.

Sediment Basins shall be designed with a storage capacity of 1,800 cf/acre.

Silt fence fabric must be buried 12 inches below grade.

Silt fence fabric must have a tensile strength of 30 PSI.

Seedbed preparation requires scarifying the ground at least 4 inches deep.

Concrete & Reinforcement

Concrete Fundamentals

The Concrete Mix — Ingredients

Cement, sand (fine aggregate), coarse aggregate, water.

Portland Cements

Type I, normal — general purpose cement. Type II, moderate sulfate resistance. Type III, high early strength — used when forms must be removed early. Type IV, low heat of hydration — used in massive concrete placements such as dams. Type V, high sulfate resistance.

Admixtures for Concrete

Water reducing admixtures (sometimes called plasticizers) reduce the water-cement ratio or increase slump. Superplasticizers (high range water reducers) are added to low/normal slump concrete to make high slump flowing concrete — typically turning a 2-inch slump into a 7-9-inch slump. Retarders are used to retard the rate of set (sucrose is a common retarder). Accelerators are used, typically in cold weather, to accelerate early strength development (calcium chloride is the most common accelerator).

Air Entrainment

Air entrainment reduces bleeding, improves pumpability and impermeability of concrete. Air-entrained concrete contains many microscopic, evenly spaced air bubbles. Air-entrainment improves concrete's resistance to freezing and thawing cycles and the application of deicing chemicals.

Without proper air-entrainment, concrete will scale and spall. Variations in air content affect durability, placeability, finishing qualities and yield. Higher temperatures, lower slumps and coarser sand reduce air content.

Testing Methods

Slump: The slump test measures the consistency of concrete, indicating workability, plasticity or flow. Higher slump indicates wetter concrete. Most specs allow one addition of water on the job prior to discharge when slump is below spec, taking care not to exceed the water-cementitious material ratio (w/cm).

Compressive Strength: measured by the average strength of two test cylinders. Compressive strength (f'c) is measured at an age of 28 days.

Formwork: Form liners provide special textures or patterns. Snap ties hold forms in place while concrete is placed. "Slip forms" are used to form curb and gutter.

Pumping Concrete: If pumpability is a problem, consider reducing aggregate size. Rounded aggregate, such as "river rock," aids pumping. Pre-wetting or saturation of the aggregate is key to eliminating problems pumping lightweight concrete.

Reinforcement

Unreinforced concrete has high compressive strength but its tensile strength is only about 10% of its compressive strength. Reinforcing steel should be placed near the bottom of a concrete beam to resist tensile forces. Lowering the top reinforcing bars or raising the bottom reinforcing bars by 1/2 inch or more than specified in a 6-inch thick slab can reduce its load-carrying capacity by 20 percent.

Concrete Placement and Finishing

Elapsed time for placement should not exceed 90 minutes or 300 drum rotations. When pouring into forms for walls, beams or columns, the stream should not be allowed to separate paste from aggregates by falling freely over ties, spacers, rebar or embedded items. Floats for finishing air-entrained concrete should be aluminum or magnesium, not wood. Final finishing of a slab should not begin until the surface sheen of water ("Bleedwater") has dissipated. Vibration consolidates concrete and removes large entrapped air voids; remove the vibrator when bubbles stop appearing on top. The appropriate method of vibration is fast insertion, slow withdrawal.

Common Field Problems

Excessive bleeding can be alleviated by increasing the portion of sand, introducing air entrainment, or increasing cement content. Plastic shrinkage cracking results from surface tension created by rapid evaporation of surface moisture, primarily caused by low humidity and high wind. High slump concrete may result in segregation of the mix. Air entrainment will sometimes cause blistering of concrete.

Reinforcing Bars

Standard bars are "deformed" bars; deformations vary by mill and help concrete adhere to the steel. Deformed bars are designated by a bar number indicating the size of the bar in eighths of an inch — a #5 bar = 5/8 in. diameter. There are eleven standard bar sizes — #3 to #11 inclusive, and #14 and #18. The minimum standard bar size is a #3, or 3/8" diameter.

Bar identification is set by ASTM specifications, which require the bar producer to roll the following onto the bar: a letter or symbol showing the producer's mill; a number corresponding to the bar size; a symbol or marking indicating the type of steel; and markings designating the grade.

Splicing of Bars

Lapping or splicing of bars is often designated in bar diameters, such as 40d. There is no standard splice for reinforcing bars, but the minimum splice for any bar is 12 inches.

Concrete Cover or Protection

Concrete cover is defined as the distance from the outside of the bar to the surface of the concrete. Minimum concrete cover for a bar cast against and permanently exposed to earth is 3 inches.

Types of Joints

Contraction (control) joints control random cracking; depth should be at least 1/4 the thickness of the slab. Isolation joints separate a slab from an adjacent structure such as a wall or column, allowing for vertical and horizontal movement of building segments. Construction joints provide a stopping place for a day's work.

Joints and Reinforcement for Slabs on Ground

Welded Wire Fabric (WWF) is used in slabs on ground solely to prevent cracks from opening — it does not otherwise reinforce the slab. Fiber reinforcement (secondary reinforcement) does not affect jointing recommendations. Recommended overlap for WWF equals the grid size + 2 inches — e.g. 6x6-w1.4 x w1.4 wire fabric would be lapped 8 inches. WWF should be placed at mid-depth of a 4-inch slab; in slabs thicker than 4 inches, place it 2 inches from the top.

Estimating Quantities

Masonry

Building Brick Grades

SW (severe weather): used where bricks are exposed to freezing weather and saturation with water. MW (moderate weather): used where there may be exposure to below-freezing temperatures but not likely permeated with water. NW (no weather): designed for use as backup on interior masonry.

Facing Brick Types

FBX: must be uniform in size and color. FBS: for general use in exposed exterior and interior masonry walls. FBA (irregular or architectural): manufactured and selected to produce architectural effects.

Brick Sizes and Quantities

Modular Brick — 4" x 8" x 2 2/3" (nominal dimensions). Use a quantity factor of 7 bricks/sf. Mortar quantity: use a factor of 5.5 cf/100 sf. Three courses of modular brick = a height of eight inches (3 courses = 8").

Pattern Bonds

Running bond — all stretchers in each course. Common or American bond — header courses used every fifth to seventh course. Flemish bond — alternate headers and stretchers in each course. English bond — alternate courses of headers and stretchers. Stack Bond — where all the joints line up — is the weakest bond of masonry.

Concrete Masonry Units (CMU)

The weight of an 8" x 8" x 16" CMU made of sand and gravel is 40 lbs. The nominal size of a standard 8" x 8" x 16" CMU is 8" x 8" x 16"; the actual size is 7 5/8" x 7 5/8" x 15 5/8" to allow for a 3/8" mortar joint. Two-core (hole) block is best for reinforced masonry walls — more space for conduit/utilities and a thicker shell at the center web.

The flange of a CMU is laid in the up position — it aids picking up the block with one hand and provides a larger bed joint surface for the next course. Control joints in a CMU wall should be filled with caulking compound to a depth of 3/4". CMU basement walls below grade should be dampproofed with 1/2" thick Portland Cement parging. Lintels for a CMU wall are typically made of precast concrete beams.

Concrete Masonry Unit Quantities

Block: use a factor of 1.125 blocks/sf. Mortar: use a factor of 6.0 cf/100 sf.

Mortar Properties

Hydrated lime is available in two types — S and N. Only Type S is recommended for use in mortar mixes. The compressive strength of mortar is increased by adding cement. The most significant property of mortar is the bond strength.

Laying Masonry

The squareness of the slab should be checked by measuring the diagonals (equal if square) or by using the "6-8-10" rule. The mason line should be set at least 1/16" away from the face of the block. Laying the corners of a brick masonry wall is called "laying the leads." Batter boards establish and preserve building lines during excavation and construction — before placing batter boards, the builder should "pin the building corners." When cleaning bricks by sandblasting, use low pressure (60 lb. to 120 lb.) and a 1/4" sandblast nozzle. Corrugated metal wall ties shall be 22-gauge metal.

Characteristics of Brick Veneer

3"-4" nominal single wythe, anchored to a backing system of wood frame, masonry or concrete. Not part of the structural system — supports no load other than its own weight. Has an airspace between the veneer and the backing. An adjustable wall tie attaching masonry facing to a backup system should engage the facing unit by a minimum of 5/8". A cavity wall usually consists of two walls separated by a continuous airspace 2" or more wide — 2" is the most common. A curtain wall is an exterior nonloadbearing wall not wholly supported at each story. Efflorescence is a deposit of white powder or crust on brickwork surfaces caused by soluble salts drawn out by moisture. Raft and matt foundations are used over soils with low load-carrying ability — also called "floating foundations."

Carpentry & Associated Trades

Drawings

A window list on a set of plans is called the window schedule. Working drawings are the most exact and extensive drawings used on a project. Elevation drawings show front, side, and rear views of a building. Floor plans are typically drawn to a 1/4" = 1'0" scale. A Benchmark is a starting point or point of reference (POR) from which measurements can be made — a mark on the foundation of a nearby building, or a stone or concrete marker on the ground at a certain location.

Lumber Defects

Check: a small crack that runs across the growth rings, parallel to the grain. Shake: a lengthwise grain separation between or through the growth rings. Boards shrink more proportionately in width than length or thickness.

Doors

A 3 1/2" butt hinge is used for a 1 3/8" interior door. "Standard" interior door height is 6'8" (80"). Door stops should be installed after the lockset and strike plate have been installed, and the door is latched, and are permanently installed (nailed) on the lock side first.

Framing

Plywood soffit boards are attached to the structure using 4d nails spaced at 6" o.c. Nail fascia boards to rafter tails.

Insulation

Batt insulation placed between floor joists above an unheated crawlspace should be well supported between the joists by wires or wire mesh. The vapor retarder on the batts should be placed toward the "warm-in-winter" side. Fiberglass insulation is a skin and lung irritant — wear protective clothing including a long sleeve shirt, gloves, long pants, high-top work boots and a cap, plus a suitable dust mask or respirator and eye protection. (Note: Mold-resistant clothing is not required.)

Interior Carpentry

Screws used to mount a cabinet to a wall should have at least 1" penetration into the supporting member. (Remember to add mounting board and gypsum thickness to screw length.)

Roof Framing

Ventilation for hip roofs should be provided by eave vents in soffit boards.

Manufactured Trusses

Trusses should be unloaded as close to the building site as possible. Trusses stored horizontally should have blocking on eight to ten-foot centers to prevent lateral bending. Trusses stored vertically should be braced and blocked in a stable manner to prevent toppling and sliding. Pitched trusses should not be stored with the peak down. Scissors trusses should not be stored with the peak up. Trusses should be placed a maximum of 1/4 inch from the location indicated on the plan dimensions. The maximum allowable lateral deflection permitted when lifting a truss is 3 inches per 10-foot section. The minimum size lumber that may be used as temporary braces for trusses shall be a minimum 2 x 4 x 10'. Braces should be attached to trusses with two 16d nails. No loads should be placed upon trusses that have not been properly attached and braced. Maximum out-of-plumb tolerance for a truss is the lesser of D/50 or 2".

Roofing

Underlayment (Felt Paper)

Drip edge should be installed under the felt at the eaves and over the felt along the rakes. Drip edge should be a minimum 28 gauge galvanized or other non-corrosive metal.

Built-up Roofing

Bitumens used in built-up roofing are either asphalt or coal-tar pitch.

Asphalts Used in Built-up Roofing

Type I (dead level). Type II (flat). Type III (steep). Type IV (special steep).

Application Temperatures

Types I & II asphalts should not be applied at a temperature lower than 350°F. Types III & IV asphalts should not be applied at temperatures lower than 400°F.

Cold-applied Bitumens

Asphalt emulsions are made of fine droplets of water dispersed in asphalt with an emulsifier such as bentonite clay. Apply asphalt emulsions at the rate of 3 gallons per square. (Note: A square is 100 square feet.)

Repairing Leaks

Leaks around vent flashings are usually the result of improper shingling around the flashing. Minor cracks and worn areas on asphalt shingles can be repaired by applying roofing cement and sprinkling on loose granules, rubbing them into the roofing cement. Damaged asphalt shingles can also be repaired by installing galvanized sheet metal beneath the shingle and nailing the metal in a bed of roofing cement, then covering the nail heads with plastic cement.

Roof Maintenance

Being walked on is never good for a roof. Make sure accessories (antenna wire and anchors) are of non-corrosive materials that will not stain the roof. Never pressure clean an asphalt shingle roof. Remove branches and leaves from roofs.

Repairing Wood Roofs Damaged by Hail

A wood shingle or shake roof is considered beyond economical repair when the repair costs exceed 80% of the replacement cost.

Sheathing under Wood Shingles and Shakes

The maximum board size recommended for use as sheathing under wood shingles or shakes is a 1x8.