![]() It's all 'doable', but as mentioned by Rafe/Richard above it is not trivial to change your roof support structure around. As well as you now have to have a way to structurally attach the roof rafters to the proposed structural ridge beam and also have structural support posts at the ends to support the structural ridge beam all the way to the foundation. Next, unless you just 'happen' into a big steel I-beam for cheap, I think you'll end up spending more for the steel and the shipping and the installation (just can't pick up a 24 ft long big-a$$ I-beam by hand, even with a couple of 'buddies' helping) than that ~$750 for the LVL's.Īnd the 'next' next, tying in the roof rafters into a ridge beam and eliminating the ceiling joists or cross-ties/collar-ties changes the entire load structure on the roof rafters (roof rafters would probably have to be beefed up as well. (translation: You'd have to go even bigger with your 'homemade' beam than the LVL version). The "design values" for the LVL will most likely be 'better' than you can get with #2 lumber. Ix-nay on trying to 'build your own' laminated beam from a bunch of 2x12's sandwiched with plywood. If this were me I think I'd contemplate building a lower profile hoist before I modified the building. It'd be expensive to replace all the collar ties with steel, but it'd be quite strong. If you were able to make the sissors truss from steel 2x4x5/16" wall thickness box beams with reinforcing at the joints you might really have something. Maybe you'll need to remove 9 collar ties or maybe a lot less. Then you can construct reinforced rafters and build a sissors truss system to occupy that area. What you might do is consider that you don't need to remove all the collar ties, but rather just those where you plan to place and use the hoist. They take a fair bit of engineering to get right unless you are planning on overbuilding everything by a factor of 3 or 4. You wanna pull the collar ties, but you are aware that they keep the building from falling down under roof loading so you wanna do something to reinforce the walls holding them together without collar ties. I am just a little perfuzed about your design. There are beam calculators on the internet You have seen the tire dollies that they sell, you put one under each tire, and then you can move the car in any direction that you want. Of course, if your driveway has a severe slope, this might not be a good plan. Buy some equipment moving gear, roll the equipment out of the garage, do what you need to do, and roll it back into the garage. What really makes more sense is to do your lifting outside, and leave the roof alone. This would give you more headroom in the center of the garage, but not at the side. You get more storage space also, although you might need a rolling ladder to really make good use of it.Īnother approach would be to buy replacement roof trusses, cathedral style, and install all the new trusses before cutting the old ones. That way you don't alter the structural integrity of the truss. I think that it might make more sense to jack up the entire roof, trusses and all, and then add a couple of feet onto the side walls of the garage. The lower part of the truss is what keeps the weight of the roof from pushing out the side walls. ![]() Yeah, I have a professional engineering license. What you are proposing is really non-trivial, from an engineering perspective. ft on the roof for dead and live load, and again, 24X24 6 pitch asphalt shingles. That is one huge beam for a small garage, and will cost over 750.Īnybody want to size a steel beam, figure 40-50lbs load per sq. Local lumber yard sent out for calculations, came back with (3) 1 3/4 x 20 " deep LVL microlams. Beam will be supported at both ends, clear spanning 24 Ft. This would task the ridge beam with supporting about 500 lbs per linear foot. a total load of around 12,000 lbs, this reflects 1/2 the load on the outer bearing walls, half supported by the ridge. North East snow load, I come up with approx. In short I need to size a beam that will be set under the existing ridge board and create a structural ridge so the cross ties and collar ties can be removed. I want to remove the existing ceiling joist/ties that keep the rafters from spreading the walls in order to get a cathedral open area so I can use my car lift to it's full height. Have and existing garage, 24'x24' with straight gable roof.
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