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Thread: Increasing Garage Wall Height?
02-13-2009, 11:59 PM #1
Increasing Garage Wall Height?
i was wondering if there are any accepted ways of increasing the wall height of an existing 2x4 framed garage? starting construction would be a slab with what i would guess is a perimeter footer/rat wall. with the sill of the wall bolted to the footer. i'm thinking of a increase in height of 2 to 3 feet.
ways that have crossed my mind, but of which i have no idea that would pass muster would be.
1. build a small framed wall of desired height increase, lift garage and secure to new mini-wall.
2. lift garage lay a few course of block and sit garage back down on blocks.
3. lift garage poor small wall and set garage ontop of wall. i'm guessing this would require saw cutting slab/rat wall and replacing with new poured footer and mini-wall, leaving the existing slab 'floating' inside the garage.
also on another front is there a way to increase the height of a pole barn that is too short?
02-14-2009, 12:19 AM #2
If it is a detached garage – and what we call western platform framing (2x4 framing sole plate & top plate) then detach the earth quake anchors and go along jacking up the structure a 2x4 width at a time every 4 ft until you reach the desired height.
Bolt some extensions onto your former anchor bolts to bring them to the new height. Form for concrete and pour it “wet” with vibrator
02-14-2009, 12:27 AM #3
I have seen houses with pier and beam foundations raised and moved, but how are you going to stop the walls from colapsing when you disconnect them from the slab?
02-14-2009, 12:31 AM #4
what's up rudolf,
i would advise against building a short wall made out of wood framing materials. if you stack walls like that you create a hinge in the wall,which becomes a failure point. you really need to make it out of a masonry material. your easiest way would be to use block. you would need to add horizontal rebar and i would attach all-thread from the existing anchor bolts through the new wall to the bottom plate of the existing wall. i assume there is a very real need for this. it seems to me a lot if work, and i do this for a living. if you insisted on using wood framing you could probably get away with stacking walls if you added a stud that went full height every 4 feet. the code in cali requires that stud to be a 4x. but your not in cali. i would tend to lean towards masonry or tear down and rebuild.
if you rebuilt it would be a good opportunity to make the shop the way you want.
02-14-2009, 12:43 AM #5
02-14-2009, 07:42 AM #6
i be tempted to jack it up and sister the 8 foot studs with 10's
would be sound when your done with no seams
if you knocked out the top sills you could put the new studs next to old ones and not disturb siding
that would also leave the old walls mostly intack (you'd only knock out one sill at a time) to have the jacked up roof tied to so the whole damn thing didn't end up in the neighbors yard upside down
02-14-2009, 09:32 AM #7
I just don't see how raising the walls of an existing garage off the floor can be cost effective. You'll have to redo all the door openings, lower any windows, redo all the wiring, and reposition anything that needs to be within reach.
Raising the roof and leaving the walls in place is a little easier, but the task of disconnecting the roof from the walls is more difficult than disconnecting the walls from the floor.
It's difficult to give advice without knowing more about the size, type of construction, and how it's finished. As always, a few good pictures would really help.
02-14-2009, 10:50 AM #8
If you believe raising the roof is your best option, here is how I would do it.
I would cut the studs about 12" from the top plate. How doesn't matter, a chain saw would work. You can do this to every other stud without much fear of problems. Then you can attach cripples that extend down to the bottom plate to these short upper studs.
Now you can set up your lifting equipment. You may need to buy 4 or 6 "Widow Maker" (handyman or hi-lift) jacks. When you are ready to lift you can cut the remaining studs and any other attachments.
The jacks should allow you to raise the roof a couple of inches at a time, while the cripples you attached to the top plate and short studs will help keep the roof in place.
If for some reason you need to stop your project, you can nail or screw the cripples to the original studs to temporarily secure the roof, and resume when you are ready.
02-14-2009, 10:59 AM #9
This isn't raising...it's lowering, but may give some ideas...
A neighbor wanted to lower his barn down so that the loft floor was at ground level. He then planned to take the loft floor out so he was left with a building with about 20-25 feet to the peak instead of the 10 foot main floor he had before.
He cut through the walls all the way around the building just below the loft floor with a chainsaw. He then started at a door 3 inches down from the first cut and went around again. As he cut, he pulled out the 3 inch "strips". By the time he got back to the door, the main floor was 3 inches lower. Repeat....
Took him a lot of cutting, but it only cost him some gas and a million chainsaw blades.
02-14-2009, 11:03 AM #10
My preference would be to add wood (studs or a mini-wall), or as second choice, put in a block knee wall. Pouring a wall underneath a suspended building doesn't strike me as a good idea. Roger makes some valid points about raising only the roof.
Timber frame buildings commonly use half lap joints to make longer timbers. I expect this could be done to make your poles longer on the barn.
My suggestion would be this - If the Ann Arbor construction market is anything like the one in North Carolina you should be able to find experienced, licensed Professional Engineers who are desperate for some work. When I needed an Engineer's approval back in '03 for a cantilevered wall it only cost me $175 (thereabouts IIRC). Call around and you can probably find one that will give you some structurally sound options for both projects.
Another option would be to call folks who raise buildings for a living and have likely seen something similar.
02-14-2009, 11:38 AM #11
This is a job for an experienced garage building crew. I don't think a few inexperienced men should be doing this.
It would be cheaper to rip the roof off and extend the studs and rebuild the roof with trusses. If it already has trusses they can be reused most likely.
If you want to raise it a concrete block wall under it would be the safest way but as mentioned all the door openings would have to be lowered. The windows would be to high to look out but that's good, no one can look in.
Just how big is this garage?
02-14-2009, 11:38 AM #12
This garage used to be 24' X 24' x10' high at the front, flat roof, 6" X 6" post construction. I raised the original roof to 12' in front and 15' at the rear, now the center peak, then added on. I sectioned the 6 x6 posts with custom made 11ga 5 1/2" x 5 1/2" x 2' angles bolted together. It is now 48' X 50' .
I bought a three stage mast forklift, chained and clamped the roof to it and did the lift, front first then the back. I had to brace it to lift. The new addition is 6" x 6" post with 2 X perlins. I did all this by my self, I only hired out the concrete drop and finish, I did the grading and forming.
02-14-2009, 01:38 PM #13
New block first floor - mighty sturdy.
Hope the image shows - this is the oldest standing house in Miami, Fl - it *was* a one story wood house till the main got married, he then jacked it up and added a concrete block (block made on site) first floor. Hurricane Andrew (Cat 5) hit shore about 5 miles south of here in 1992. We lost the roof on the cupola on the top of the house. Period.
02-14-2009, 03:19 PM #14
okay here are some pictures of a possible garage to lift. i just walked it off but lets call it 24' x 24'.
however this question is not specific to this garage. due to the state of the michigans economy there are a wide selection of properties on the market. i have been looking at properties for a while but few if none have met my price point or needs. seems that often they are lacking in acceptable shop space. i have found several where the garage or outbuilding looks okay but it too short for my desires. my current space has 11' 11" inside height and i would really like 10' minimum but would rather have 12'.
tearing it down a garage or outbuilding and starting from scratch really doesn't make economic sense here and for me as far as i can tell. complete properties can be had with land, house, and generally some type of garage or out building for the cost of constructing a decent outbuilding that would suit my desires. there are two other basic considerations in the mix. more likely than not any michigan purchased property will be a long term destination for me, therefore no sense in dumping the wad on a outbuilding since i probably won't have it long enough to recoup any large costs. second is that for me incremental cost in smallish bites are much easier for me to handle and self finance. as we all know the days of cheap and easy credit are mostly over.
one of my main concerns about doing the block riser wall is whether the existing footer/rat wall would support the additional weight. a while back when i was looking at some block garages with the same thing in mind i talked to a couple of masons. they said if you have an existing block garage with 8' walls the footings should take up to about 12' walls fine. mind you that these weren't engineers just masons that work in the field and i was asking for a rule of thumb opinion. certainly i could go hire an engineer but right now i'm just trying to get a feel for what is possible as i look at a variety of properties.
re concerns about windows, doors, and wiring. those aren't really concerns for me. windows will most likely all be deleted on any structure i own. doors generally from what i have seen doors need to be replace anyway and even when new didn't meet my security requirements. wiring, not a problem for me i spent years wiring industrial applications, that and all the properties i have looked at need new feeders at the least because the feeders are too small. i guess what i am saying is without raising the wall height i have already planned on addressing all that other stuff. i have reworked a fair amount of old structures and i would guess working by myself and not counting acquiring materials the window delete, door rehab, and wiring could all be done in a month.
so basically i'm looking for all the suggestions and insight that i can gather, from those that might have seen something applicable or that have been there and done that, so keep it coming .
02-14-2009, 05:39 PM #15
if the structure already has trusses, than lifting the roof only might be the best idea. you could disconnect the entire roof structure as a unit and lift it the desired height. then as wippin boy suggested, sister all the stud with longer studs. i don't think adding 2' to the height would require any additional foundation work, if the original was built in modern times. but as always an engineer on site would be able to answer that the best.
02-14-2009, 05:54 PM #16
Maybe there is something I am missing, but all of the people that are mentioning the doors and windows are going to be the wrong height are definitely on a different path than my thoughts.
I would do it just as I saw a garage repaired after a truck was driven through the back wall. They simply took a LOT of timbers (normally used in house moving) and stacked them on the existing concrete floor under the corners and load bearing sides of the trusses. Then they jacked up one side of the roof (after removing all wiring and hold-downs) and added enough timbers to hold that side. Then they did the same thing on the other side. They came in and replaced the broken walls, and then lowered the roof back down to the walls after the mortor dried. Replace the wiring and hold-downs and your back in business. Simple to just add a couple of extra timbers to get the roof higher, so you can add additional courses of block. Repour the sil and your in business. Since you added blocks to the top, you didn't change the doors or window heights, so that shouldn't be a problem.
David from jax
02-14-2009, 06:16 PM #17
Ok sandman, if the door opening is 80" off the floor and you lift the whole building off the foundation 24" now the top of the door will be 104" off the floor. Now you will need a door that is 104" tall. I think you will have to make the door. Wilt Chamberland will, however, be able to walk in without stooping over.
In the first post it says he wants to raise the ceiling height of the garage. There is only two ways to do that. Raise the whole building or raise the roof.
02-14-2009, 06:46 PM #18
Years ago I saw a picture in the local newspaper of a terrace of small houses that had their tiled roofs and chimney stacks supported on acro props (1 ton rated poles with a screw theaded section), sitting on the first floor. The first floor was sitting on more acro props on to the ground. All the brick walls had been removed!!!
After having seen this I advised a friend of mine who wanted to raise his brick garages roof to do the same, loads of acros, 4 courses of bricks on top of the old wall, job went really well.
The real problem with an old wooden structure is the wall plate, it keeps both the roof and walls in line. If the plate is lifted with the roof, in order to keep the rafters where they should be, the walls will walk out of true. If the wall plate is left on the wall studs, then the rafters will collapse. the other thing you must be aware off is that the roof must be lifted squarely (1" per 10' allowed?) and it must always be restrained so a gust of wind won't be a disaster.
I would remove the top covering plank (or two), assemble new extension studs say 6' long, drill through the "top" of them about 3" down and two holes in the overlapping section, say 3' apart, all on the centre line. Tighten up all acros, then cut of first stud about 6" down from the plate. Put new extension stud up against it, drill right through and fix with a bit of 1/2" threaded rod, and big square washers, put big "G" clamp on bottom of old and "new" stud. Repeat, if things are getting scarey, drill through the bottom holes and fix old and new studs with threaded rod as you will do to finish. Else lift, clamp, lift, clamp. . I would triangulate the top joint with gussets, or 45 degree braces to the trusses.
02-14-2009, 06:47 PM #19
The other way to raise the ceiling height is to lower the floor.
02-14-2009, 08:19 PM #20