site built rafters for garage

[jdaley]

Can somebody help me. I have built a garage with site built rafters. They are supported by two 14 foot 2x8s as the ridge. Yes there are rafters on each side of the seperate 2x8s. They have 2x6 collars on every rafters. All rafters are plywood gusseted both sides glued and nailed. There are stem wall supports at about 5' 7" these are also 2x6. These supports rest on 2x8 floor joists that span 13' 10 1/2" wich rest on a 10x12 beam. Do these rafters have to be engeneered.

 

[SWComposites]

Why do you care? You have already built the garage.

 

[JStephen]

Usually, 1-story houses are exempt from state requirements that would require design by a PE. In most states, you can download the rules from the state board of registration and confirm more closely what is and isn't exempt, and how your structure fits in.

Many localities will also follow building codes that specify construction details. You'd need to check with the local city or county building department to see what they require.

 

[AlohaBob]

Whether your rafters are okay depends on the species of wood you use, snow condition, wind conditions, roofing materials, seismic conditions, connection details, roof geometry.

I suspect an engineer could review what you have in less than an hour.

 

[boo1]

additional designs can be found at:

http://www.public.iastate.edu/~mwps_dis/mwps_web/tr_plans.html

 

[jhall]

you should have a licensed engineer check the design. The members may work but it is usually the connections that fail first.

 

[Stress02]

It would seem that if you have concerns, have it reviewed, especially if you own it.

There is also the question how the overall structural system works, not just the member size. For example, are the rafters tied at the rafter bases or does the ridge have to serve as a true beam? If the ridge needs to hold the rafters up, is it properly sized.

Many unknowing house designers make the mistake of just throwing sizes at members without knowing how the system works. I have seem many houses with the walls pushed outward due to improper design approach.

Regarding Engineering, in our state, each town's local building official has the last word, so if there is doubt in his mind, whether the code requires an Engineer or not, you may be required to engage one if the Building Official says so.

I know of several who require all residential beams be Engineered even though the code does not require certain sized residences to have a Professional involved.