My New House & Workshop

[Jim Oaks]

Since it seems that it would be easier to raise the joist and not try to support the old cut joists to create a pocket, this means that the whole width of the shop would be higher in that area. With that being the case, it makes more sense to have my work area running with the width of the building instead of the length. If I line it up with the side doors I could pull right in to that opening. Doing it this way also means I'm modifying less rafters. From what I see, if I move (4) ceiling joists higher, it will give me a raised ceiling that's roughly 16' feet long and 6'8" wide. If I raised (5) ceiling ceiling joists my work width becomes 8'. Doing it the other way I was going to have to raise (6) ceiling joists. For what I want to accomplish, I feel like (4) joists and 6.8" (6'7" after drywall) width would be plenty wide enough to raise a Ranger up in to.

 

[Rick W]

@Rick W said:
Cut the roof from one side to the other as wide as you want.
@Jim Oaks I'm not understanding what you're saying.

I’m talking about cutting from side to side in two places, and then jacking up the section in between. Cut in between two joists, not too close to either, and make sure you have enough room to build the side wall under the high roof.

I would temporarily support the new ends of the existing roof on either side (before you cut) until the raised roof has its end walls tied in. There’s a little bit of design to those end walls too, so they hold the high roof up, square, and protected from wind loads, and it should also support the ridge on the low roofs.

You need stub walls above the block on each side. & if you go this route, it’s peanuts to add 2-3 feet to what you’re planning so you can fit a lift inside later. If you want to go this route, let me know, and I’ll do some sketches for what those high end walls should look like.

& this goes back to my bump out design, a modification of that plan, for the big truck. If you cut and raise the existing roof about 2 feet higher than your planning, you can cut out the block the width you want, and put a little tiny steel I-beam across the span between the block walls, the stub wall on top of that beam. Do the bump out as far as you want, frame three walls shorter than the stub wall above the beam, and then just build a shed roof with 2 x 4 or 2 x 6 shed roof that comes down to the top of the newly framed walls of the bump out. You don’t have to reframe the roof.

Again, I’m happy to sketch if you ick what you want

Rock

 

[Rick W]

Random thoughts:

RE: structural ridge. Part of the reason for the structural ridge is to keep the rafters from flopping over like dominoes from front to back or vice versa. You have a “federal“ roof design. It doesn’t just slope up and slope down from side to side. It does that in the middle but when you get close to the front, it also slopes to the front of the building. I don’t have a picture to confirm it, but it does it do the same thing in the back?

That 90° Turn in the slope will keep the roof from racking like falling Domino’s up to the point cut across. With the 1x decking, I suspect is tongue and groove, there’s plenty of integrity to keep one rafter from moving relative to the others, and with that front 90° roof slope, that’s basically is the brace that keeps it from racking in either direction.

If you raise the roof completely from side to side in one section, we have to brace it with angle braces that run along the length on the low roof on both sides, and also on the high roof to recreate the “racking” protection. Wi’ll figure that out if you go with this option. Not hard, but has to be done,

 

[Rick W]

Random thoughts:
@Jim Oaks said If I'm understanding this correctly, you're saying to mount (scab) a 24" long 2x6 along the opposite side of the rafter that the ceiling joist is on, and mount it to the top plate next to the original rafter. This I'm guessing is to keep the rafter from cracking under the down force of the roof. Does it have to be screwed to the top plate as well, or just screwed and glued? What size screws and what kind of glue? While I'm thinking about it, is there an advantage or disadvantage between wood glue and construction adhesive like liquid nails? Every time you say glue I keep thinking construction adhesive.

Close, but upside down. When you move the horizontal up, it creates a smaller higher triangle that is self-supporting. But now, the outside ends of the triangle are pushing down on the angled part of the rafter where it attaches to the triangle as opposed to tying in on top of the wall. The way the rafters are now that triangle sits into and on top of the wall with only downward force, no outward force, because the horizontal member is in tension and won’t let it move out.

The scab has to be an exact duplicate of the bottom of the angled rafter. It has to start two or 3 feet higher (than triangle end) towards the peak, but it runs down to the wall, not up to the pea. in the exact same shape as the existing angle part of the rafter, so that the scab also sits on top of the wall.

Basically, you’re doubling the width of the angled rafter between the top of wall to 2-3’ up past the triangle end. You will still have a bending moment at the point where the triangle connects to the angle rafter, and you will still have a force to push it out. But by doubling up the rafters, you’re just more than doubling the bending integrity of the rafter in the free spot. You’re building a heavy member that will resist breaking, just by increasing the brute force resistance.

In the picture, the horizontals were connected by bolts. Again, it’s not actually the bolts that hold the strength. The bolts push the two pieces together, and it is the friction between the two pieces that creates the strength. Gluing the members is like welding steel as opposed to bolting steel. It’s not a little bit stronger, it’s much much stronger. When you’re doing it, you need to make sure there’s nothing that would keep the two pieces apart, like a nail head or knot that’s pushing out. You want to run a zigzag of waterproof liquid nails where the loops are maybe 3 inches apart over the whole length. Then I would use 2 1/2 inch torx deck screws. If you sync them a quarter inch or so the point will be within a quarter inch of the other side. If your not handy with the screw gun, You may have to pilot drill The board where you start the screw, or you’ve got to hold the piece in place with clamps, so as you put the screw through, you make sure that when the screw goes through the first one, it doesn’t push the second one out before it tightens down. The goal is to pull the two pieces together. I’d put two screws at the end, and then I would alternate one hi one low about every 10 inches or so. That’s just to make sure there’s good contact the length of the board. I wouldn’t do it, but after the glue sets, you could actually remove the screws and use them on the next one. But building inspectors like to see the screws.

As regards code and building inspectors, my focus is on strength and stability of the structure, and some of my suggestions are probably overkill. The codes are designed for the minimum that is safe. You’re dealing with a shallow roof so we have to overcome that by beefing up some of the pieces. If you go with this stuff, I don’t think it would be hard to get variances from the code Providing you can demonstrate it accomplishes the code intent, it’s durable and strong. I was going to bring that up when you settle on the final design. If it’s pretty straightforward I wouldn’t worry about it, but if we’re doing something weird I’ll discuss with you on how we might wanna get a structural engineer to just sign off on a couple of pieces. If it’s like here that’ll cost you two or $300 and it’s great insurance.

 

[Rick W]

I made a few important edits to my last post, reread it

@85_Ranger4x4 said Probably not "up to code" but after all this talk about rafters I have been gawking at my barn roof as I work on my camper. It seems to be sort of a hybrid. Looks like a structural ridge with lengthwise running beams that are supported to the floor.

His is absolutely beautiful, And built like a brick out house, but it’s apples and oranges to one at @Jim Oaks has. I’m not seeing much that would transfer over to watch him he’s trying to do. I’m not crapping on @85_Ranger4x4, Obviously he’s a good guy trying to help.

 

[Rick W]

If I'm understanding the point of this correctly, the higher the pitch the more force that's pushing the wall down and less force that's forcing the walls and rafters to spread apart. Since the pitch is so low, it wants to push the rafters and walls out, which is why there has to be a single solid joist as low as possible to hold them together

This may be repetitive, I just want to make sure I answer everything. The triangle, whether it’s sitting on the walls or the triangle is formed higher up on the angled rafters, the ends of the triangle push straight down.

The outward force on the walls is controlled by the Horizontal part of the rafter. So, if that horizontal part of the rafter is higher than the top of the wall, the angled rafter in between the triangle and the top of the wall will still be pushing the wall out. The solution is doubling or tripling the width of that free space extended a couple of feet above the end of the triangle, so it won’t bend or break.

 

[Rick W]

It also looks like the person bolted the new truss in place with (5) bolts. Is there an advantage to bolts over screws? Especially since there's so much concern about load force? Don't screws have clamping strength and bolts have sheer strength? Would I be better with bolts versus screws and glue?

Again repetitive, but it’s the glue that carries the strength. Yes, the bolts have much greater sheer strength, but that could actually be a detriment if the bolts ever come loose. At that point and just below it is where we’re talking about a very large bending force. If you glue the wood to the wood, those forces spread over every square inch of the contact. If you use the deck screws, they do minimal damage to the fibrous natural structure of the wood. If you start drilling bigger holes, and you do get a twist, those holes will be a point at which the wood will split and fail. Like the screws, the bolts are to hold the two pieces together to create friction. If you do that temporarily with the screws or bolts and you use glue, the glue is taking the whole load after it sets and it won’t fade with time if the screws or bolts come loose.

BTW, some of this stuff is partial answers because I don’t want you make your head explode with stuff that would have no effect on what you’re doing

 

[Rick W]

Are you telling me to keep part of the original crossmember because I need it, or because you think I want a ceiling there? Is the 2x4 parallel 'strap' meant to support the remaining section of original ceiling joist and drywall? At this point I'm thinking it would be easier to ditch all of the old ceiling and joists in the areas where I install raised joists. The peak in this design gives me some room for the GMRS antenna mounted in the center of my cab. LOL. I'd have to piece in 2x4's between the joists at the peak to screw drywall to. This method looks like it may be a little more difficult to put together than the R4 idea.

Leaving a piece of the existing horizontal part of the rafter is a minor fine point. If you cut it along the edge of the angled piece it’s not much different than cutting it square below the point where the two flare out. The tiny advantage of keeping it square is that it just holds the end of the original angled rafter on top of the wall steady and it will help it from splitting. This is probably accomplished by gluing the scab on the other side, so cutting it square is not that big a deal.

Having said that, I would not remove the part of the existing horizontal that sits on top of the wall and overlaps with the angle part of the rafter. But the horizontal away from it, but don’t mess with the end, it’ll probably just cause more trouble.

So yes, if you leave it square, you’re going to have a little bit more sheet rock work. But if you cut it off at the angle matching the underside of the angled remember, you can sheet rock that up to the horizontal, sheet rock across, and then sheet rock down on the far angle.

Again, other longitudinal braces will be required if you raise the roof up, but not necessary if you keep the existing roof in tact

 

[Rick W]

What did I miss?

 

[Rick W]

Here’s a much easier bump out couples with raising the roof section

The size of the beam and how it sets on the wall has to be designed.

&, BTW, in keeping with last comment, these drawings may not be quite ready for construction...

 

[1990RangerinSK]

@Rick W said:
Cut the roof from one side to the other as wide as you want.
@Jim Oaks I'm not understanding what you're saying.

I’m talking about cutting from side to side in two places, and then jacking up the section in between. Cut in between two joists, not too close to either, and make sure you have enough room to build the side wall under the high roof.

I would temporarily support the new ends of the existing roof on either side (before you cut) until the raised roof has its end walls tied in. There’s a little bit of design to those end walls too, so they hold the high roof up, square, and protected from wind loads, and it should also support the ridge on the low roofs.

You need stub walls above the block on each side. & if you go this route, it’s peanuts to add 2-3 feet to what you’re planning so you can fit a lift inside later. If you want to go this route, let me know, and I’ll do some sketches for what those high end walls should look like.

& this goes back to my bump out design, a modification of that plan, for the big truck. If you cut and raise the existing roof about 2 feet higher than your planning, you can cut out the block the width you want, and put a little tiny steel I-beam across the span between the block walls, the stub wall on top of that beam. Do the bump out as far as you want, frame three walls shorter than the stub wall above the beam, and then just build a shed roof with 2 x 4 or 2 x 6 shed roof that comes down to the top of the newly framed walls of the bump out. You don’t have to reframe the roof.

Again, I’m happy to sketch if you ick what you want

Rock

When did you change your name to Rock?

I was actually thinking similar to what you're talking about earlier this morning, after I saw the email. Two things I would add to your idea: first, an eight by twelve beam running the width of the shop, under the walls holding the raised roof; second, under the center of each beam, given that the length of the beam is sixteen feet, a minimum six by six post (make sure this post is on a proper footing, NOT ON THE SLAB).

My beams and posts are probably overkill. With the weight Jim is dealing with, he could PROBABLY get away with four by four beams, and he could probably get away with no posts. But, I like overkill.

Oh, build the roof with the peak parallel to the beams that hold it up. Build it with gable ends, and then you can put windows up in the gables, and have some natural light.

@Jim Oaks One problem you're going to run into with your raised ceiling going across the width rather than along the length is that at the ends of the raised section, you lose clearance. I like the direction Rick is going. I'd say go six rafters, just to give you some room. Maybe even seven or eight. You'll have more room. And, as Rick suggests, if you raise the roof there, you can raise it enough to add a lift (not important to me, but you might want one). You can also add windows to the gables, if you build a gabled roof perpendicular to the existing roof. Oh, and, unlike my drawings yesterday, this one won't fall down, especially if you run beams, as I mentioned to Rick.

 

[Rick W]

I joked about my drawings being construction ready, but that’s a fact. I understand where @1990RangerinSK is coming from on the beams and posts. With every respect, it is a little overkill, but he’s right it will never fall down.

I’m not just looking at the structural integrity, I’m also looking at how in the hell would you get it done if you do it. The junior I-beam i’m talking about across a garage door opening is something you could manage without a cherry picker or a forklift. 2-3 guys can muscle it up.

As regards the gable walls and windows, absolutely, I’m just leaving that as a detail for later after you decide which structural plan you’re going to pursue.

Whatever design you decide to pursue, then we will zero in on the details to make sure you have structural integrity for the roof and anything you might want to hang off the roof, like an engine and transmission.

Right now, everybody’s goal is to provide you with alternatives and suggestions. But again, none of this is ready to build. When you zero in on what meets your needs, we’ll get you covered on the details.

 

[Jim Oaks]

How did we get back to cutting open the roof and building it up higher with windows?

I just want to find a way to move the ceiling joist up 10-inches on my rafter. I thought a possible solution was gluing and screwing an additional 2x6 to the side of the rafter from the top plate to 24-inches higher than where the new joist sits (10 inches higher).

Was @Rick W Saying to cut the old joist even (angled) with the bottom of the rafter?

Apparently there was concern about supporting the cut end of the old joist (where I wanted to add a box / tray) by hanging it off the new joist, so I figured I'd ditch that and just drywall the whole length of the new joists from wall to wall.

 

[franklin2]

The method below looks the simplest, using screws instead of bolts and putting the 24 inch piece on the other side.

You probably only need to buy a couple of 2x6's. Do all the work and get the new higher 2x6 ceiling joist in place above the old one, cut the old one out and use it for the next section. Once you get that section done, you will cut the old 2x6 ceiling joist out and use it on the next section. Of course you may need some short 2x6's for your 24 inch pieces.

 

[don4331]

@Jim Oaks

I was on the same page as @Rick W & @1990RangerinSK ; but I'm with you now. And I know how to do what you want (and I'll tell you how to make it to code while we are at it)

You want a steel I- beam at runs from block wall to block wall on either side of the area you intend to lift the ceiling*. On top of those I-beams, you install a column that the supports the existing ridge board. You are now ready to turn the existing ridge board into a structural ridge board**. You will need to cut back the existing rafters enough to slip 2x boards on either side of the ridge board, gluing and screwing them to the existing ridge board, then screw the rafters into the new boards. The structural ridge board also sits on the columns on the I-beams. You do need to check that we aren't concentrating too much load on the outer wall - you might need a longer I- beam over door - it wouldn't just be supporting rafter ends, but also distributing the structural I-beam load, so might need e.g. 4' on either side of door.

With the above, the ceiling board is not longer required - you can completely remove it and drywall to the rafters if you so choose. That way, you could get almost 30" additional height at center.

I don't know exact dimensions for the I-beam/structural rigid board - you need a local engineer to confirm those. A column from I beam to floor allows smaller beam, but would probably be in the way a lot of the time

* Ideally, you want 2 more I-beams, one at each end where the end hip meets the side, along with columns and structural board running the entire length of building. Note it can be under your existing right board, you shouldn't have to turn your existing ridge board into a structural one. Then with structural ridge board, you meet current code.

**Might want some temporary supports during construction, so a storm does does apply Murphy's Law.

I can draw pictures after work if description doesn't make sense.