datsunlover Posted April 3, 2007 Share Posted April 3, 2007 So this is a shop problem more than a car problem, but hey.. you gota have a shop to build a Z in right! My FLAT ROOF garage is sagging and leaking.. go figure... At this point, I have almost compleated the nessasary (as I see it) bracing and structural suporting from inside with two new 4x10 headders/posts/ect and I need some advice/thoughts from other people... The layout is a little strange, bacause the 'main' garage is a 23 long X 14 wide building, and probly within 5 years (a guess judging by the simmilar building methods) a small addition was added to one side, which is 14 long X 10 wide. The small addition is at the front (attached to the back of the house) so it is basicaly a 24x23 with the back corner 'missing' on one side. (it juts in 4' from the rear, and over 10') SO... the roof is built with 2x6 joists, (running front to rear) covered with 1" boards and on top of that is what remains of a tar/graval covering, pitched slightly to the back yard, and not very well either.. The back yard grade is HIGHER than the garage, and of course what water does manage to run off the roof goes right into the garage. Need to do some retaining wall/gradeing back there.. It's not a 'downpour' but almost ALL the boards in the roof are wet. Very wet.. actually, waterloged... ANYway, I'm trying to figure out if I can just put a pitch on the roof and shingle it, so I can eliminate the water issue and insulate the garage. (I'm thinking I would rather do something that would be more of a justifiable 'repair' rather than take the roof off, get a building permit, engineered trusses, and the whole bit..) What I've come up with is a small steep pitch at the front, 3' rise, 2' run back from the front, (which would match up to the rear wall of the house) and a long shallow pitch from that to the rear. Say, a 22' run from that 3' hight.. I'll have to see if I can get a picture to illistrate this.. I'm thinking I don't need a permit or anything for this.. or am I wrong? (this would be built right over the existing roof, obviously with all the gravel/tar remains scraped off) Anyone got suggestions/insight? I am really against re-taring it, as I think a flat roof is utterly stupid in this climate (There was about 5 feet of snow up there this winter, and a LOT of water when it melted over the last few weeks!) but I'm willing to hear opinions.. My thinking though is it's probly just as much money and I'd be left with the same situation in a few years time.. Either way, something MUST be done.. I don't think the poor things got another season left in her, and I really want a shop for next winter.. Oh, and forget demo and building new: I can't afford to, and even if I could, the one wall is ON the property line so I'd never be able to re-build where it is, and the property is too small to put a new building anywhere else. Thats my sad story, what do you think? Any help/info is appreciated guys. Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted April 3, 2007 Share Posted April 3, 2007 sketch it out on a piece of paper so that i can see it better and add a picture. i will help out as much a possible. its what i do for a living. jimbo Quote Link to comment Share on other sites More sharing options...
zuhow Posted April 3, 2007 Share Posted April 3, 2007 For a shingle roof, you need minimum 3' fall per 12'. With wet snow you might have some problems, but I've got 4/12 and haven't had any problems. You should have a permit, but really that depends on your neighbors. I'd look into a standing seam metal roof if I were you. It won't be cheap, but much cheaper than new engineeringed trusses and a what not. Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted April 3, 2007 Share Posted April 3, 2007 metal roof is great for a long time. expensive but will last for decades. the main problem it sounds like is the sagging of the roof which nothing will really fix except some additional beams under them or new roof members. may not be a cheap fix anyway you look at it. jimbo Quote Link to comment Share on other sites More sharing options...
datsunlover Posted April 3, 2007 Author Share Posted April 3, 2007 metal roof is great for a long time. expensive but will last for decades. the main problem it sounds like is the sagging of the roof which nothing will really fix except some additional beams under them or new roof members. may not be a cheap fix anyway you look at it. jimbo Well, yah, that's why I'm adding bracing inside (it is almost 10 feet high in there!) with 2 laminated 2x10s spaning under the existing 2x6 joists suported on the outside wall by 2x4 posts (3 to 4 2x4s laminated together) down to the floor. (aprox 14' span) and in the middle from a hanger bracket to the OTHER 2x10 (2 laminated together) beam I ran from the front of the grage to the corner that juts in (small addition section) I'll try to do some drawings tonite, showing the original construction, what I've done so far and what I'm hoping to do. I'll try to sketch out what I'm thinking for the roof too, and see if my girlfriend can scan them for me, then I can post them later tonite or tomorrow. As for the pitch, I know the current 'code' says 4/12 pitch on 24" centers, but I'm thinking if I brace it well, even a 2/12 pitch on 16" centers would be better than the FLAT that it is right now! The structure does take the snow load as it is, and the saging is probly not that big a deal, except that it allows pooling and seeing that the covering has degraded, it now soaks through and leaks.. I've been driving around town and have noticed a LOT of garages built similar to mine, that have obviously had a pitch of some sort 'added' to the roof. Some go straight up from the front wall 2-3 feet and pitch back to the original flat roof hight, some pitch back off the front about 2' (like what I'm thinking) and then pitch back, givng it sort of a a skewed peak.. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted April 4, 2007 Author Share Posted April 4, 2007 Ok, so I got some sketches done up and uploaded.. lets see if I can post them now... First off, the 'floor plan' such as it is.. (The pencil wasn't very dark, so it didn't scan well..) The red is extra bracing/work I've done already There was nothing but original 2x6 joists, saging pretty bad, and two were cracked in the small addition area. (after I jacked evrything up level again and put the beams in, I added 'sister' boards to the sides of the cracked ones) The blue is the other beam I'm hoping to add tomorrow/this weekend. Another pair of 2x10's laminated together with a post on the far side wall, and a hanger bracket on the first beam/header I put up already. I'm thinking I may also put another post to the floor, roughly where these meet, for extra support. (say about 2.5 ' from that rear corner, cause there will be a work bench there anyway..) As I said, the current joists are almost 10 feet from the floor, so I'm not concerned with loosing hight, I just want this thing to be sturdy and not fall on me! The next two are my basic idea of what the roof could look like.. The peak being built off the flat rof, and directly on top of the current front wall; Curently, the facia borads are there (about 8" and wrap around the whole garage) and the front has a 2' overhang towards the driveway. The 2x6 roof joists continue past/over the front wall and create that overhang, so I figure it'll take the small weight of a short pitch. It's the main roof that has me woried, as the water pools right in the middle now, and you can see a definate sag to the pair of dinky 2x8's they used in the middle of the span. (the blue lines on the first drawing) So.. whew... What do you guys think? Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted April 5, 2007 Share Posted April 5, 2007 I think that would work. But why don't you raise the peek a little to increase the pitch? Quote Link to comment Share on other sites More sharing options...
datsunlover Posted April 6, 2007 Author Share Posted April 6, 2007 I think that would work. But why don't you raise the peek a little to increase the pitch? Well, a few reasons.. First, it's not shown in the drawings, but the side of the house has a section that 'pops out' from the wall about 2 feet, only one story high and has a small roof section on it. (It's actually part of the kitchen where the sink and some cabinets are.) If I were to build my garage roof like I've drawn, the front of it would match up well with that existing (house) roof, making a nice 45 between the two. (no crazy angles to try and build, not to mention possible water leaking issues in the future..?) Second, more pitch would mean more lumber, sheeting, shingles, ect... A bit more $$$, but my main concern now becomes weight... And at some point, it's probly less weight and almost the same cost to put engineered trusses up there! I'm just trying to keep it simple and not too expensive... At one point, I had the thought of building a sun room of sorts up there, as a second story bedroom is in that top corner, and the floor would be the right hight for a nice walk out... but AHHHGG!!! the 'while I'm at it' syndrom!!! You know? Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted April 6, 2007 Share Posted April 6, 2007 ok, it looks pretty easy. i did a quick calculation and a 5 1/8x12 glu-lam beam will span the 15' +/- that is where the pitch is. it wolud rest on the existing walls with posts. then you could hanger 2x6 joists @ 24" o.c. for the front pitch and then 2x12's at 12" o.c. now this should meet the local code. the problem is that the reaction of the beam is over 4000# which means the need of a footing. now with that being said, you could probably get away with 2x12 @ 16" and not see the roof sag at all. 24" and i am willing to bet that the roof will start to deflect to the point that you could see it. do not want that. you might be able to get away with out the footing depending on the soil bearing pressures in the are and the width of the existing footing. can not tell you that one. just post up the glu lam so that the top of the beam is at the ridge line and nail it down. you could leave the existing framing as is. the snow load would not be applied to that part anymore. hope that helps. jimbo Quote Link to comment Share on other sites More sharing options...
datsunlover Posted April 6, 2007 Author Share Posted April 6, 2007 Hmm... well, thanks for the input.. although.. for the rear (long) span... you're saying.. 2x12?!?! wow.. I thought maybe 2x8's with bracing down to the flat roof (where the joists run, 16" oc) about every 4 feet.. Or would that not work? Either way, it seams I' may have to get a permit regardless.. I've been talking to some people localy, and it may not be too much hassle.. I'll have to go down to talk to the building inspector, explain what I want to do and he'll probly want to come have a look at it. He may say 'nope, you don't need a permit, thats a 'repair' job. Go for it." BUT; if I just go ahead and do it without asking about a permit, well.. apparently the local inspector can be a really big dink... and cause me all sorts of crap. Also, from what I'm hearing, since the structure is already exsisting, they can't make me change too much, maybe put in extra 2x4s for strength.. but the way I see it, I'm tryng to make it BETTER so why would the town have a problem with it? Just means they can raise my taxes a bit next year... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.