Truss Technician Training - Level I Sample Exam ANSWERS This exam has been developed by the Wood Truss Council of America (WTCA) to prepare you for the types of questions that will be asked in the proctored TTT Level I Exam. A separate Answer Sheet is also available. The exam will cover the following five basic categories of information. Truss Math The use of geometry, trigonometry, and algebra in the design of trusses. Truss Standards Standards and documents pertaining to the design, manufacturing, and use of metal plate connected wood trusses. Structural Design Basic engineering principles, statics, strength of materials, load development, and load paths. Building Codes Design load and performance requirements applicable to wood trusses as specified by building codes and engineering standards. Wood Technology Basics understanding of lumber grades and the natural and in-service factors affecting the strength and performance of wood and wood trusses. This sample exam will present at least one question from each category. The proctored TTT Level I Exam will be much longer and you will be given a 4 hour time limit to complete it. Things to remember for the proctored TTT Level I Exam: Bring a calculator and any books, binders or notes you have used while taking the course. These will be allowed. Computers are NOT allowed. Use the space provided on the exam to show all work or include additional paper as necessary. Partial credit can be given. Numerical answers not accompanied by the calculations will be considered incorrect. You must do your own work without assistance from anyone else. 1 of 4 Truss Math Sample Question #1: Fill in the chart below: PITCH RISE RUN HYP TAN SIN COS Angle 9.8 103.15″ 126.3″ 163.07″ 0.8167 0.6325 0.7745 39.23º Sample Question #2: A truss has a 8/12 pitch, a 1/4″ butt cut, and a 2x4 top chord. a) What is the plumb cut height of the 2x4? Ө = Tan-1 (Pitch/12) = Tan-1 (8/12) = 33.69º Plumb = (lumber/cos Ө) = (3.5 in./ cos (33.69º) = 4.206 in. b) What is the heel height of the truss? 4.206 in. + 0.25 in. = 4.456 in. 2 of 4 Truss Standards Sample Question #3: Who is responsible for communicating the design criteria from the construction documents to the Truss Designer? a) Truss Manufacturer c) Contractor b) Owner d) Building Official Structural Design Sample Question #4: For the loading diagram shown, find the reactions R1 and R2. R1 = 3,666.7 lbs. / R2 = 2,833.3 lbs. 3 of 4 Building Codes Sample Question #5: What is the total weight (in pounds) of a 10-ft by 10-ft floor area consisting of one layer of 20 lb. felt, 3/4 in. plywood sheathing, and 1/2 in. interior gypsum board? (Use Table C3-1a of ANSI/ASCE 7-98) Area = 10-ft x 10-ft = 100 ft2 1 layer of 20 lb. felt = 0.2 psf 20 lb./100 ft2 3/4 in. plywood sheathing = 2.4 psf 0.4 psf per 1/8 in. thickness (0.4) x (6) = 2.4 psf 1/2 in. interior gypsum board = 2.2 psf 0.55 psf per 1/8 in. thickness (0.55) x (4) = 2.2 psf Total Dead Load in psf = 0.2 + 2.4 + 2.2 = 4.8 psf Total Weight = 100 ft2 x 4.8 psf = 480 pounds Wood Technology Sample Question #6: a) What happens to the strength of wood as the temperature increases? Strength of Wood Decreases b) What is used to “adjust” for the strength properties for lumber used in high temperature conditions? Ct 4 of 4