Need some help with a idea for a addition.

Started by schiada, February 23, 2019, 01:06:03 PM

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schiada

My Wife wants to add a room off the kitchen. I would like it to be a open space. Its on the eave side of a truss roof (photo). Its a track home that we have been in since new.(35+ years) We would need a beam to span about 20'. The black line is the new beam.
   

I'm thinking that a support could be added to take the truss roof load and lift it a little to be able to install the new beam.Think I could remove the drywall on the ceiling and add a cleat for the jacks to take the load.

This is all out of my pay grade. I will need to get a outsider/builder and was looking of a answer before getting that started. You guys have been a big help with my other project that is on hold for now.
My Wife and I are needed to take care of her Mom now. So a lot has changed but its all good.

We are trying to build a little bigger space . A place for some of her stuff that is important from her past.

The room will be about 21' x 12' with a truss roof to be tied to the original roof .This will be on a slab.

So what do you think ?

Randy

Don_P

What is the span of the existing truss, which I assume is the back wall in the pic.


schiada

Thanks,Don for helping. Span is 25'.



Is this what you needed ?

schiada


Don_P

I'm assuming the addition is trussed and only adds a small amount of dead load for the field framing of the valleys. I'm also assuming there is no or very low snow load there, that wind controls, so 20 psf live load and 15 psf dead load should be conservative. Half of the present trusses bear on the left end, half on the right. So the tributary area bearing on the new beam is 12.5'x 20' beam span=250 square feet x 35 lbs per square foot= 8750 lbs total load
http://www.timbertoolbox.com/Calcs/beamcalc.htm
LVL's come 1.75" thick, I tried 11.875 deep x 7" wide (4 plies)
Fb is 2800-3000 psi in most, E typically 2.0, Fv 280 and deflection passes for a roof ( I think I was a bit conservative in loads as well)
If this is to be exposed, a glulam beam would be a better option, the size would likely be similar. If this is getting too deep you are probably looking at steel, shooting from the hip an 8" W shape at some weight (they come in different weights/strengths) would probably work.
The truss supplier can also supply the beam and will provide engineering free of charge as part of the service of the sale, they should do the final sizing, this is simply getting you in the ballpark.


schiada

Thanks Don.
I will start looking for someone here !
Just didn't want to be dreaming.
Randy