Attic Trusses

[TeaMan]

I agree. Most of what I'm doing here is for me so I can visualize the room size and let my wife see it in 3D. I've thrown out about 3 plans so far when we looked inside in 3D and found things didn't fit at all. We finally like the plan I'm working on but need to cut some corners because believe it or not, the area we now live in has very few houses in the price range we are building and we are having problems with financing because there are no comparable sales within the last 6 months. It's a dumb game, but we are in it now.

TeaMan

[DJ1979]

I work as a truss designer at the local plant here in VA would be glad to help if you would like. Could possibly get you some drawings of the trusses if not in a big hurry as I am getting backlogged

[TeaMan]

Sure DJ, I wouldn't mind. I need to go over my plan dimensions today and make some suttle changes. I found out that when I changed to SIP walls, the dimensions got messed up.

You can see from all the previous posts that I'm looking for an economical way to put a bonus room over my garage. I made a slight change and made the pitch of the roof over the attached garage a 10 by 12. It was 8 by 12 previously, but didn't seem to yield room of the right size and also messed my roof line up a bit. The width of the garage is a 23' span. I kind of like the cathedral truss Curtis came up with but would also settle for a flat ceiling if the cathedral isn't doable. PM me with your email and I'll send you floor plans and elevations.

Curtis. As you can see above I went to a 10 by 12 pitch and it yields a nice room. Problem is I drug the roof plane for the roof of the house that is perpendicular to the garage to the end of the house which caused it to drag through the bonus room. Now I have a roof inside my bonus room. I'd like this to be my roof line. Do you know of a way to cut that piece of roof out of the bonus room without messing with it outside the room?

TeaMan

[Curtis Johnson]

Tea Man:

That is the fun part of CA ... learning how to do roofs and edit them manually ... if doing them automatic doesn't work. What you need to do is try to visualize (probably from a birds eye view ... or other angles as needed) how the roofs should intersect. If you are an SSA member and can watch the videos on creating roofs ... watch them all and practice what you see. If you don't have access to the videos, then it would be best to zip your plan and post it.

By the way, if a ceiling plane is parallel with a roof plane, that is usually called a "cathedral" ceiling; if the ceiling plane and roof planes are not parallel, like my example, that type of ceiling is usually called a "vaulted" ceiling.

Just a suggestion .... if possible ... use even foot dimensions ... more user friendly for materials, layouts of trusses, etc. If you could do your building at 24' rather than 23' wide, that might eliminate some extra cutting of sheathing materials etc. Not absolutely needed ... just a recommendation.

[TeaMan]

Thanks Curtis. I knew that about the cathedral and vaulted ceiling, I just keep getting them mixed up. I don't work with it enough.

Hey, when you lay a plan out, do you lay it out from the outside or inside of the walls. IE, if you were to build a 24' X 40' building, would that be the outside or inside of the walls? I would assume outside, but when you create them in HDP it measures inside and when you click on a dimension to move a wall, it's the inside, not outside. I think that's why my dimensions are kind of goofy. I think I need to move some walls to make it correct.

TeaMan

[Curtis Johnson]

Best to use the outside main layer to set your dimensions to if you can. I only use the inboard dimensions when determining "living area" and when dimensioning interior partition walls for ICF homes.

Don't you have any control of where you dimension to with HDP?

[TeaMan]

There is an arrow on the layers for the wall and a check box that says to dimension to his point, but it always goes to the outside of the siding, rather than where I put the arrow. I'm not sure if it's because I created the wall type as a SIP wall or not. I can't seem to get it to change.

Everyone I spoke to today says the outside walls get dimensioned to the outside of the sheeting and the inside walls to the center of the wall.

My only recourse is to set the outside dimension as if it was the outside of the sheeting and ignore that it really is the outside of the siding. I suppose I could also try removing the siding layer.

TeaMan

[Curtis Johnson]

Check your dimension defaults first and make sure that they are set the way you want them. Then double check your wall definitions and make sure you have the correct wall layer checked as the main layer. You can change these around as needed.

I don't dimension to the center of interior walls - I go to the side of framing. When you layout locations of partition walls on a subfloor, it is much easier to put your layout mark on one side and the an X on the side of the line where the framing will be installed. If you put your measurements to the center of walls, then when laying your walls out, you have to measure over 1/2 the thickness of your wall framing to have marks you can snap with your chalk line. If someone else is building from your plans and your measurements are to center of framing, they won't be tooooo happy.

[Curtis Johnson]

If you are using SIPS, make sure the outside of the exterior sheathing for the panel is your main layer. The bearing capacity of the panels is based on the skins (sheathing layers) and the foam working together as a unit to carry any overhead floor and/or roof loads. The recessed sill plate should measure in 7/16" (typically) from the edge of your foundation treated plate. If being erected on a floor system, then just set back your recessed plate from the edge of the subfloor material. The SIPA website has all sorts of details for SIPS panels.

[TeaMan]

Thanks Curtis. I finally got the dimensions to go to the outside of the sheeting. It was a combination of defaults and SIP definition. I'm not sure exactly what worked, but it did so I moved on.

Thanks for the tips on the SIP's. I've been reading a lot on the Enercept site. I'll try the site you suggested also.

TeaMan

[Gene Davis]

I got asked to design the upfit for an above-garage space, one for which the original designer just banged in a "bonus room," done using a scissor truss arrangement above, and floor trusses below.

"Bonus room." I dislike that term because it implies to the buyer that he or she is getting free living space for nothing, and the buyer is often led to believe all the footage is usable. IMHO, an architect or designer doing such a space should at least show with phantom lines, a scheme or two for upfitting it to actual living space. The client would then know what the space delivers, and whether it is worth building up to gain it.

In this space I was asked to upfit, the kneewalls are all at 51 inches above rough floor, with the scissors-truss bottom chords at a 6:12, and a huge amount of the thought-to-be-available space was lost to "attic." Client thought he had a nice opportunity in a 28x28, 784 sf space. He got a whole lot less than that, and was not happy.

If you want to see all the building details of an upfit above a garage, one in which the contractor wrecked off the original roof, re-did the roof with scissors trusses, and then did all the inside building and finish, all to achieve a really great guest suite, check out the long pictorial thread by Mike Smith, of Jamestown, Rhode Island, on Taunton's "Breaktime" web forum. Mike is a Chief user, a great builder, and likes to do these beginning to end pictorial stories, using the web forum. Find the thread in the Photo Gallery section, titled "## Garage to Guest Suite."

[Curtis Johnson]

Another problem with many "bonus rooms" is that they are built with not so good detailing, especially with regard to insulation, and can tend to be not so comfortable, at least in areas with real winters. Similar to problems some people have with their floors over crawlspaces. Therefore, the bonus may not be a bonus at all ... except to the pocket book.

[Gene Davis]

You got that right, Curt. In this one I did, I had to point out to the client that unless we did some serious work down below, in the uninsulated and unheated garage, that the plumbing would freeze, servicing the new bath and wet bar. We go to 40 below a few times each third winter or so.

Client said he would work out valving and drainage with his plumber, so it would all be "safe," and that the new space above would only be used in summer.