Rough estimate

[LSMFT]

I've one estimate (too high)done. I have a roof on a house 22' by 24' that is low (4ft at peak). I want it ripped off and put a gambrel style to utilize the upstairs space. That involves removing and disposing the old roof. Laying down a sub floor, erecting rafters, sheathing and shingling. Does NOT include siding, windows or any inside work, I will finish it myself. I thought $17,000 was too much considering I can have a brand new 2 car garage on a slab built including siding and doors for $6900 in this area. Anybody have a similar job done? How much?

[h]

Can't tell if it's high - where are you?

[dpb]

Not to mention there's no mention made of whether there's adequate foundation and other structural for adding the second floor loads, etc. Who's doing that? The existing ceiling rafters won't support a load-bearing floor so it's floor joists before subfloor and, as noted, something to hang/set them from/on...

At $30-something/sq-ft doesn't sound out of line; no...

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[aemeijers]

I'll second that- unless you already have 2x8 joists on the correct centers in the 1st floor ceiling (unlikely with an attic that shallow), this is more like adding a 2nd floor than replacing the roof system. First floor structure and foundations will need to be taken into consideration in any case, especially if this new attic is to be rated as living space. If you really want to pursue this, you need a site survey by a qualified architect or engineer. You can save some bucks if you can come up with a set of 'as built' blueprints for the place. A professional opinion will likely be required before they let you pull the permits.

If you have room on the lot, I'd compare the costs with doing a 1st floor bumpout or ell. Engineering is simpler, and disturbance to existing footprint is likely to be a lot less. And it won't fry the head of the folks in the inspector's office.

[Ed Pawlowski]

A place I pass on the way to work sells pre-fab homes. They have a couple of garages on display for $25,000 for a two car garage and attic. Given that price compared to yours, the $17,000 for a new roof sounds reasonable. The tear down and disposal is probably $3k of that.

[Tony]

Am I right assuming that if the current ceiling/roof is trusses, then you would have to remove them first, which means you will have no ceiling, and a big mess of wiring to deal with?

I am now picturing a more engineered approach that would possibly make things a lot easier, but I'll wait to see how wrong I am here so far!

[Tony]

Hell, if a new garage is that cheap, can they attach it to the house, delete the garage doors and ad some windows and doors? Then you can finish it as you like?

[Tony Hwang]

Hmmm, More involved and complex than building a garage(people don't dwell in it) Can't compare this project to a garage building.

[willshak]

LSMFT wrote the following:

There is a lot of labor tearing a roof off a house, besides the cost of removal and disposal of the debris. If you had to tear down an existing garage to build that new one, it too would cost a lot more than $6900. $17,000 would be cheap where I live.

[jamesgangnc]

Doesn't sound out of line. I'm just guessing that the contractor is probably planing manufactured roof trusses to deal with transfering the load to the exterior walls. Stick built would require figuring out how to support a new floor load above the existinf structure. He'll have to order those and they won't be cheap.

[LSMFT]

This house was built in the 1940's. It has 2 x 6 joists in the first floor ceiling, same as the 2 x 6 joists in the floor.

[jamesgangnc]

2x6 don't span a whole lot. Not by todays standards anyway. They on 16"? Might be good enough to put a floor directly on. I'm guessing since it's a small house and the proposed 2nd story floor space is in the center that there will be some potential load bearing walls under it. What's in the basement, posts? A 2x4 interior wall can carry a fair load but it will need support under it in the basement. If it's stick built the load will have to transfer through interior walls as well as exterior. A manufactured truss can transfer more of the load to the exterior walls. Still, tear off the old, dispose of it, build the new and roof it, $17k doesn't seem so bad. Get a couple more and that'll tell you. I'd also want to ask for some details on how they plan to do it.

[LSMFT]

Yes, it has a 6 x 6 beam across the center of the basement with steel posts on concrete pads. That should hold thing up don't you think?

[jamesgangnc]

The other thing to look for is how far some of the interior walls that might become load bearing are from the 6x6 beam. You need them to be pretty close otherwise you are transfering load via the floor joists of the 1st floor. They will deflect. Image lines through the existing structure going up from the basement support to your new 2nd story floor. You don't want a lot of horizontal travel via the 1st story floor. If the basement is unfinished you can also place additional steel posts under the interior walls that will become load bearing if needed. From what you have said it does sound like your plan is doable. The contractor you pick should be thinking about all these things and should look in your basement and ground floor to confirm how he plans to support the new floor. Ask him questions, he shouldn't mind explaining his plans to you.

[dpb]

LSMFT wrote: ...

Maybe, maybe not...that's what you need an engineering evaluation for.

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[jamesgangnc]

While there's not a downside to having an engineer involved, except cost, I'm think a good general contractor could also evaluate this and come up with an acceptable solution. Since the op is already concerned about costs adding a grand or 2 to have an engineer calculate loads is probably not his prefered path. Just saying.

[dpb]

Can't see from here...

I'm not tellin' anybody to add a second story on existing foundation, etc., w/o having such "minor details" verified...

Permitting will probably require it anyway. Just sayin'...

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[h]

Agreed. We'll be doing the same thing in the fall, and our contractor scoped out the foundation before he gave us the quote. Not only will new joists be required for the new second floor, he's got additional structural supports going into the basement. We've had the plans drawn up and some architectural drawings done, so the inspector will "get it". Our tiny town has an ancient building inspector, and if he can't see it like a photograph from every angle, inside and out, he won't approve it even if you have detailed blueprints. We learned that from past experience. We wanted to build a pre-fab garage, and he wouldn't approve it until he saw a "picture or drawing of the finished garage, on your lot." Huh? How do you take a picture of something that doesn't exist yet? Answer? Photoshop is your friend. So...we have our drawings so he'll approve the new permit. He never even looks at the blueprints! I love living in the boonies, but small town gubmint is tricky.

[jamesgangnc]

I'm not suggesting that this forum is the go/no go authority on this. I just suggesting that a competent general contractor should be able to figure out how to support this without requiring an engineered design.

[Tony]

And probably most places by now need "sealed plans" (blueprints with the seal of a registered architect) to get a building permit. Although there are still some place like here, no plans needed, no blueprints needed. Pretty much the rule here is to build it on your land and don't cross the property line. That's about it. Only thing they inspect are sewage and electric. For real.