Chance to expand my garage (!) - need some framing advice

[Tim]

Sadly, the massive elm tree beside my garage is dead. Means it has to be removed (50' tall or so). My 80 year old garage is a few feet away from it.

With it gone, I have an opportunity to expand my limited 12 x 20 garage by 4 feet. While not a massive increase, it will allow me to actually have a bike on a table and be worked on without having to constantly shift stuff around. As it is, in my 12 x 20 shop, I have:

MINI Cooper Clubman
R75/6
SR500
XS650
TU250X
3 bicycles (one hanging)
Tool cabinet...

You get the idea. So to work on a bike, the car leaves the garage, which is fine. But, to put the car back, the bike has to be moved back to its designated spot, which is a pain. With the extra 4 feet, I can put a lift in possibly even, and while I'd still move the car out to work most times, the lift would stay in place allowing a project bike to sit there as long as needed.

Instead of tearing the whole thing down and rebuilding, I think I can bump it out 4 feet and make it a little more interesting looking to boot. The attached drawing shows the new roof rafters and outside wall in green.

I think the sequence would be:

Layout / install new perimeter 'foundation' - basically dig down a couple feet, some tamped gravel, concrete blocks.
Build new perimeter walls
Slice holes in existing roof beside existing rafters
Remove old roofing decking etc once I confirm exactly the footprint of the new roof by dryfitting a few new rafters
Install new rafters
Deck / shingle new roof
Cut out old stud walls/rafters from inside

Thoughts? I'm assuming the new green framing I've diagrammed will be plenty to support the section of roof that no longer goes down to a wall. I'd likely use 2x6 rafters (currently 2x4).

 

[Tim]

Oh, and I'd leave the existing 9' wide garage door alone, framing in a new small one beside it. Either just a steel entry door or a small roll-up door. I'd frame it such that future expansion of the garage door was an option.

 

[Kanticoy]

Your framing design is sound and I think that it would work just fine. How are your foundations normally done up there in the great white north? I know that frost depth is a concern. You'll be in essence making the new expanded wall load bearing for the entire roof, so the footers will be important. Here, our footers are generally dug at 12 inches deep by 12 inches wide and poured with concrete. That's why I used a pole barn construction in my shop with a floating slab because concrete footers get very expensive in the end. What I am saying, is the crushed gravel footer standard construction practice up there because of the snow?

 

[ako]

I don't know much about snow, but is the reduced angle of the 4' wide green beam enough to make the snow fall off? I imagine that's why the existing blue roof has the steeper pitch.

If the snow accumulates between the green and blue you might be having some flat bikes.

*note I live in a fucking hot desert and this is a somewhat theoretical concern...

 

[Tim]

Well, 'normally' a foundation would go a solid 6-8 feet below grade. But, for something like this, most people would scrape off a few inches of earth, toss a few pebbles down and pour a pad.

This is an 80+ year old structure, or it was before I fixed it up 10+ years ago.

On one side, ironically the side I'm knocking out, there is some sort of concrete strip in the ground the wall seems to be sitting on. On the opposite side, the wall was sitting on the dirt - nothing under it. So it had rotted away and the entire structure was listing to the side.

So on that side I braced the roof, and removed sections of the wall 4 feet at a time. I built new sections of wall 4 feet wide and the right height, dug out the dirt, tamped 8-10 inches of gravel in and a line of cinder blocks. Then put the section of wall in place and lowered the roof onto it. Did that 5 times to replace the 20 foot long wall. I had to stain the sections of wall as there is only 18 inches or so between my garage and the neighbor's.

Anyhow - it's sat solid for the last 10 years. So I'll do something similar on the new walls, but better as I'll have all the room in the world to work and not have to jack up the garage while I'm doing it. It almost fell in on me a few times I think.

 

[Tim]

I have to calculate the pitch of the new roof to see if it's steep enough, but it's a small section and we don't get a ton of snow up here most years. I don't care if the shingle life is cut in 1/2 etc. The entire roof is covered in water/ice membrane and then shingles, so if I do that on the new section it will never leak. Not too concerned about that. Just want to retain as much height in that new section as possible to allow for the possible future expansion of the garage door.

 

[SONICJK]

Is it all stud wall or are there any posts?
I'm just thinking it may be simpler to Leave 3 or 4 8x8 posts for the roof support, and then add the side wing lean-to style.

 

[Tim]

It's just a stud wall. I could put a couple of posts in and even run a beam under the rafters where the two rooflines intersect, but I think with 2x6 or even 2x8 rafters, nothing is going to go anywhere.

Can always add a couple of posts in later if I need to but I really don't think it's an issue. There's a rafter every 20 inches or so (I could also add some additional ones in on both sides of the roof to double the number) and we're talking about a span of perhaps 10 feet from the rafters on the one side to the new walls on the other.

 

[trek97]

Hey bud, check w your local lumber place about an LVL engineered beam. They are kinda like plywood laminated together. A smaller engineered beam can span further and sustain more load than a saw cut beam. A 16 - 20 foot span for an engineered beam should be no problem. Then you should be able to open the wall up almost completely. As long as you properly support it on both ends.

However because it would need substantial support on both ends it would impede the addition of a wider garage door later.

 

[Tim]

I'm now thinking about 2 different directions.

One is to simply take new rafters all the way to the peak, basically replacing most of the old roof. Instead of intersecting and creating the break in the roofline.

The easiest option of course might be to just extend the rafters to meet a lower wall 4 feet further out. I'd sister new longer 2x6 rafters to the existing ones to get the extra length - full length all the way to the peak. But keep the pitch the same so I'm just building and shingling a few extra feet of roof.

Lower wall of course, but it's only 4 feet out so the drop won't be dramatic. Downside is I'd likely not be able to extend the garage door now or in the future, but I have to confirm that.

 

[Kamn]

Your best option since you are removing the current wall will be to run new rafters from the peak to the "new" exterior wall, throw up a few sheets of plywood and new shingles.

 

[Maritime]

Your best option since you are removing the current wall will be to run new rafters from the peak to the "new" exterior wall, throw up a few sheets of plywood and new shingles.

This is how I would do it. Build your new base, exterior walls and tie them into existing garage then rip old roof off on that side put new rafters in 2x6 and re-roof. Just have an old fashion barn raising, I know if I could come help we could get that thing done in a weekend. I've built quite a few sheds and cabins in 2-3 long days. I'll be in Toronto next weekend if you are ready LOL.

Cheers,

 

[Kamn]

Maritime, we should get a few others together and just get it done for him!

 

[Maritime]

Maritime, we should get a few others together and just get it done for him!

I will be in Toronto From Sat 24 Afternoon until Tuesday night we are leaving for home Wed am, I could give 4-5 hours to this as the rest of the time is to visit Family and go to the zoo but I would be happy to put in that time helping out Tim if he was ready for it.

 

[Tim]

Enjoy your time with the family at the zoo. I still have to explore what if any permits I might need to pull, and the tree is still standing.

 

[Tim]

BTW - while measurements are still needed, I'm leaning towards simply extending the roofline to expand the garage by the 4 feet. The pitch is low enough that the resulting end wall will still be over 6 feet tall in my estimation, and I'll be able to open up the garage door by a solid 3-4 feet.

So I'd end up with about a 13 foot wide garage door, making it a snap to get bikes in and out of the garage without moving the car. That's the jockeying I have to do now.

I'm going to use this pic to mock up some scale diagrams. The door is 9 feet wide as a point of reference.

 

[Tim]

Oh, and yeah, that's the dead elm, and my property is a massive 17 feet wide total. It's a big f'n tree to be sure. Looks like it's going to cost a solid $2-$3K to get rid of it.

 

[Rich Ard]

Are you able to go upward at all? I have a loft in my garage, and when the shop goes up in a couple of years, I'm not giving that up. It's a great place to lose really important stuff.

 

[Tim]

I'm trying to do this as cheaply as possible. If I was going to go up, I'd tear it down and put in a proper foundation, pour a pad and build a 16 x 20 foot garage with some nice looking dormers to allow for extra storage. Can't go too high - 18' is the max height allowed for a garage without a variance and even then, it could get ugly fast.

Just want to toss down come cement blocks, frame in new walls, re-use the plywood siding as much as possible and extend the roof to cover it off. Want to do it before winter hits so I have a nice spot to work on a bike. I've got a rigid that needs to be built!

I might buy myself the lift table I've always wanted for Christmas if I have a spot to put it. Otherwise I'll do the 'smart' thing and just build a wooden platform on casters for my project bike. I'll want to be able to move it a little bit. Most times I'd likely pull the car out to do extensive work on the bike just for some breathing room, but the ability to slide it over 12 inches and bring the car back in will be sweet.

Alternatively I need to get rid of a few bikes. I think I'll extend the garage first

 

[Maritime]

Hey, I may still be able to come help another weekend, you are a days drive away. The table on wheels is worth its wait in gold, I built one and it has made it soo much easier to work on the cx, I can keep everything in it and move it all around and out of the way when needed. It doesn;t have the lift etc. but the wheels are more handy I think.