CM Toolkit Search

Chase Placement In Floor Trusses

Question: 

Is there a general rule of thumb to follow on chase placement within a top-chord bearing floor truss? In other words, how close to the bearing point of the truss can the chase occur?

Long Term Performance Of Metal Plate Connected Wood Trusses

Question: 

How do trussed roofs perform in long-term service? Are there any reports of rusting in the nail plates, rot/insect attack, do-it-yourself modifications, or condensation and ventilation problems in the attic?

Allowable Variances In Trusses

Question: 

My framers are always complaining that the “trusses are bad.” I am looking for tolerance information that not only addresses the allowable variance in length and height, but also allowable variation in the top chord with regard to straightness (i.e. how straight should a pull string line from the top and bottom of top chord be?). Also, if trusses are set on a perfectly level wall, what variation is allowed from truss to truss (i.e. if I put a 10 ft. straight edge perpendicular to the trusses, how much can they vary in height, not just at peak or bottom but all along the top chord)?

Framing Gable End Overhangs

Question: 

What is the recommended way to frame gable end overhangs?

Impact Sound Transmission Through Floor Assembly

Question: 

A condominium project I am involved with is experiencing a sound transfer problem through the floor/ceiling assembly between the first and second floor. You can hear every footstep, from an adult to a child. The floor assembly consists of a carpet and pad, 3/4 in. OSB sub-flooring, 15 in. deep wood trusses at 16 in. on center, 9 in. fiberglass batt insulation and a 5/8 in. gypsum board ceiling. The trusses span 20 ft. with air/heat ducts between the trusses. Will an additional layer of 5/8 in. gypsum board attached to 7/8 in.

Locating A Truss Hauler In Nc

Question: 

I am looking for a company that can properly transport wood roof trusses on a one-time basis that are too large to fit into a box trailer. Trusses are to be fabricated in NC. Do you have any recommendations? Could be a specialty hauler or another truss fabricator in the area that has the special frame truss hauling trucks.

Ubc Truss Marking Provision

Question: 

I stamp the bottom chord of my trusses with my company name and the name of my third-party inspector. Recently, my local building inspector requested another stamp with the on-center spacing, the total design load and the load duration factor. I have never heard of this before and I was wondering if you had any further information on this requirement.

Information On Floor Trusses

Question: 

I am researching building products for a new home and I wanted to use metal plate connected floor trusses. When I took my plans to the builder, they cautioned me against using these floor trusses. They stated that they were not engineered products, they do not carry any kind of warranty, and they do not know how long they last over time. My basement span is 30 ft., they said trusses could not span 30 ft. I really would like to use floor trusses, but now I am unsure. Could you offer any information?

Drywall Cracking Under Scissors Trusses

Question: 

We keep having problems with dry wall joints raising on the vaulted bottom chords in the track homes that we are building. The joints run from front to back of the house and the trusses bear on the side walls. The trusses are mostly 2-point bearing (a few in the front and back of the building are tri-bearing). The trusses span 40 ft. and have a 4/12 pitch with a tile roof. Is it common to have dry wall problems as the trusses deflect? How long should the roof be loaded before hanging sheetrock? Should the heel of the truss be allowed to slide out on the top plate?

Partition Separation Lag Bolting

Question: 

Is lag bolting the bottom chord of a truss to the top plate of a wall a proper fix to correct truss arching, assuming the attic is properly vented?

Truss Uplift

Question: 

I want to get a good definition on what causes “truss lift,” when the trusses will actually raise off the top plates of interior walls (even when nailed), causing the drywall to crack. Is it from drastically different temperatures in the attic and living area?

Partition Separation

Question: 

I installed roof trusses in my house and dry walled the ceiling to the bottom of the trusses. Now I seem to have a problem with the change of the seasons. Where the ceiling meets the interior wall, a gap opens and closes – in winter it opens, in summer it closes. What did I do wrong, how can I correct it and how should the drywall be installed in the first place?

Designing Trusses

Question: 

I'm looking for a book that will provide formulas and design criteria for trusses. Can you give me any suggestions of where to find a book or fairly inexpensive software?

Hand Built Trusses

Question: 

I am building a new shop that is 30 ft. x 32 ft. I need to free-span the 30 ft. dimension. Where can I get a load chart that recommends lumber size and strategic locations of the angle braces to support the free span? I am going to field erect the trusses and stick build them on the building.

Locating A Local Wood Truss Designer

Question: 

I am planning a 36 ft. x 60 ft. clear-span horse barn with posts set 12 ft. O.C. If I use 2x6 verses 2x4 wood trusses what would the proper spacing be? The roofing is 29 ga. K-panels metal with insulation, and winter snowfall is minimal in our area.

Truss Design

Question: 

Recently, I was invited to view a newly-constructed 60 ft. by 36 ft. barn, with homemade big timber trusses as follows: 36 ft. span, 12/9 pitch, construction was 26 ft. 2x12 rafters, bracing 2x6, ceiling joists were 36 ft. boxed, 6x12 out of overlapping (6 ft.), 2x12 glued and nailed center, 16 feet of joist doubled as an 8 ft. high loft, floor trusses were on 12 ft. centers atop posts deeply anchored with good footings, roof and wall cross ties were 2x6 on edge every 24 in., floor cross ties in the loft were 2x8 on edge every 16 in., 4 ft. snow load.

Building A Garage With A Bedroom And Bathroom

Question: 

We are building a garage with a bedroom and bathroom and trying to find out what type of floor joists and roof trusses to use. The garage will be a 26 ft. by 32 ft. with a 26 ft. by 32 ft. room upstairs. But we don't want to have posts in the middle of the garage to help support the weight of the second floor.

Truss Design Factors Of Safety

Question: 

I am currently working on a project where a wood truss system was loaded with a heavy spring snow. I do not believe the load was beyond the truss's design capacity, but how do you know? Is there safety built into wood trusses? If the trusses were loaded beyond their design capacity, it would not have been for a long duration.