New detached garage - code issue, drywall or make smaller?

[Hayden]

Hello I am in the final stages of designing a new shop/garage and need some advice on a design issue that has come up.

With zoning and the way my house sits on my lot I am forced into a long narrow (19.5' x 50') RV style garage next to the house.

The 19.5' width maximized my required side yard setback and the required 6' distance from my house in order to be treated as a detached garage. I had been designing it thinking the 6' was house wall to garage wall, but I just found out this must be roof eave to roof eave, which takes another 15"+ out of my width.

If I build inside of that 6' required spacing then it is considered an attached garage and it must have a fire rated wall for the 25'+ of the garage wall that runs alongside the house (the other 25' extends beyond the house). I think this means I need drywall, which I had never planned or budgeted for.

The way I see it I currently have three options:
1) Make the building 15" narrower. This saves me a lot of money but forces me into a narrower door than the 15' I was planning. I have a 9' wide 4 post lift that will go in the garage and at the narrowed building width it will start to get difficult to park anything next to it.
2) My friend/designer suggested I put 5/8 drywall between the studs and sheathing along the required wall shared with the house to meet the fire code and leave it at that.
3) If I need drywall anyway, should I just drywall the interior or at least start with the required wall and if I decide to add more later I can. Should I also insulate inside that wall while it is accessible - for the future? I live in Phoenix and it would cost an insane amount to cool the garage so I have no intention of doing that. Is there any benefit to drywall/insulation if I'm not conditioning?

It will be a stick built stucco building if that matters.
Thanks for any advice you all can provide.

 

[blwn31]

I would just sheet rock the shared wall with fire rock, i.e 5/8" sheet rock and call it done. Sheet rock is relatively cheap and easy to hang, you can rent a sheet rock lift if you need help. Great tool to use. As far as insulation, I would insulate the fire rocked wall, you can always insulate and rock the rest later if you want to. Insulation will help keep the temps cooler longer until the building gets heat soaked. I insulated and rocked my garage addition, still need to do the attic, that's where the majority of the heat comes from. Good luck with your project.

Keith

 

[Hayden]

Thanks. That drywall is probably the nicest option, it just adds a lot to the budget.

It must be detached by some amount, there are a few windows on the house wall on the garage side.

Cooling would be quite a bit more I think. It's going to have 14x14 and 8x9 garage doors on the ends so it's never going to be real tight. My electric bill currently goes up by about $220 in the summer months and that is to cool a well insulated house about twice the sf but significantly shorter than the 14' garage.

I see you're a senior member so maybe you can help - I seem to have posted this thread twice but I can't figure out how to delete one. Do you know how?

 

[Pluribus]

Other than a few windows on the existing house, is there a reason to not attach it? Seems to me you'd get a larger garage that way. A common wall saves framing, sheathing, stucco, as well as heat & AC expenses if you're conditioning your garages. Kind of makes the drywall expense pale in comparison, IMHO.

 

[NUTTSGT]

The second thread has been taken care of. If you have issues like that, just PM me or another Mod to help out.


Yes, by all means insulate the space. Even if you have to do it little by little, insulation is an investment.

Do what you can to get a larger garage space now rather than try to add on later. Sweat equity will take your money alot farther than paying someone to do it for you. If you don't know how to do it, now is a good time to learn.

 

[CraigStu]

Make sure to use the fire rated drywall. You may only need to do the 25 ft next to the house so that is only 7 sheets. It is available in 8-16 ft lengths so easy to do event w/ a taller garage wall.

 

[rjacobs]

That drywall is probably the nicest option, it just adds a lot to the budget.

You are talking about, a 40k dollar build?

With 12' walls x 25 foot length you need 7 sheets as was already stated.

Its 17 bucks a sheet(5/8x4x12) at Home Depot...

https://www.homedepot.com/p/USG-She...12-ft-Firecode-X-Panels-14211011312/100321595

That ads a whopping 120 bucks to your project...

Lets say you want to sheetrock that whole side...

$240...


Are you required to mud and tape it by the code? I bet a 5 gallon bucket of mud gets it done with 2 gallons to spare...

 

[kaymccampbell]

I'd keep the shop the extra 15" wider, and add the required drywall. 5/8 x-rated drywall is about $13 for a 4x8 sheet.
Check with your town inspector or building department on the actual drywall/fireproofing requirement and placement.

I needed 64 sheets. The cost of the drywall, mud, tape, and a HF drywall lift was maybe $1200. Not much in the scheme of things.

 

[glentre]

Six or seven feet from your existing house makes whatever windows you have almost useless. I'd vote for eliminating the windows and attaching your new garage to the house. Working in a 19.5 width garage (18 ft inside when finished??) will be cramped and you will likely regret in the long run that you didn't take advantage of the opportunity to make the inside 6 or 7 ft wider

If you are in Phoenix, have you thought about using an evaporative cooler for your garage.......much lower first cost and operating cost as compared to standard compressor run units.

Glen

 

[MrSurly]

If I build inside of that 6' required spacing then it is considered an attached garage and it must have a fire rated wall

FIRST: You need to find out what the AHJ says constitutes a "fire rated wall".
When I built my pole barn shop, covered with metal, it was explained that it wasn't 'fire rated' because there was wood behind the metal. Even if I (for the sake of discussion) framed it with steel, I would be required to provide an engineering stamp for NFPA compliance(!) as a consequence, I had to follow a different setback.

Is the stucco, itself, sufficient or will he require steel studs? or duraRock vs Hardi backer? or cellulose fill? or drywalled interior?
Is he going to require that the HOUSE WALL be fire rated, as well?
It sounds like, so far, you are doing a lot of speculating but you really need to talk with the code guy (the AHJ) and get some actual facts to work with.

Is there any benefit to drywall/insulation if I'm not conditioning?

Absolutely, YES

It will be a stick built stucco building if that matters.
Thanks for any advice you all can provide.

have you considered trimming back the existing house eave?

 

[MrSurly]

I don't know how much more involved it would be to consider attaching it to the house...but I'd personally give that a LARGE amount of consideration. There are cost savings in the build of that portion of the wall, but no doubt cost increases that are paired with the increase in square footage. I'd bet that getting the various approvals would also require an architect and engineering services, or may not be allowed at all... but I'd sure be looking into it.

 

[nadogail]

IMHO, you will be further ahead if you consult with a local authority having local jurisdiction about your plans than making an expensive mistake based on advice from people who, in reality, have no idea of your local requirements.

What flies in New York, Texas, Ohio, Virginia, may not be acceptable in Arizona.

Good luck with your project.

 

[u2slow]

My shop had the opposite problem. No room to attach it to the house, and had to settle for a much smaller shop because it was detached. I would attach it if possible. A breezeway style may pose a win-win... wider shop and a covered walkway.

FIRST: You need to find out what the AHJ says constitutes a "fire rated wall".
....
Is the stucco, itself, sufficient or will he require steel studs? or duraRock vs Hardi backer? or cellulose fill? or drywalled interior?
Is he going to require that the HOUSE WALL be fire rated, as well?
It sounds like, so far, you are doing a lot of speculating but you really need to talk with the code guy (the AHJ) and get some actual facts to work with.

Traditional sand/cement stucco definitely has some built-in fire resistance. Sometimes its applied to 3/4" thickness instead of 1/2". Certain finishes can be even higher build (i.e coarse 'slap-dash'). OTOH, some modern stucco is acrylic-based and only a 1/8" skim finish over boarding or foam panels. Worth talking to the inspector about.

 

[Joemctag]

What pluribus, glentre and McSurly said. Those windows, if not required, like for a bedroom, are gonna look out at a stucco wall. Filling them in will also save on energy. Making the garage wider is good. If you leave a space between, 4’ is enough to get wheelbarrows and lawnmowers through.
I’d look at having an actual shared wall. This is not as simple as it once was because you might need to show how you’re gonna do the foundation at the house, and that the house wall can support your added (roof) loads, etc. Some people would avoid attaching because of the roof tie-in alone, but that can be done. Maybe need crickets to carry water to front and back from mid-point of shared length. Membrane is great for that. Your house will be open for a little while, but if you plan and have all your material, you could do your roof framing, sheathing and roofing done in a short period, with tarps every night. After the roof’s done, you don’t have to worry about rain damage in your house. And you’re saving some wall framing and some stucco to balance out the extra roof and window-filling-in work.

 

[Hayden]

Appreciate all the tips. Fully attaching it is not an option - window is required for egress, the roof on house goes one way while the garage goes the other so the garage is substantially taller for almost its entire length. It would be a nighmare.

I will probably drywall and insulate the one wall for now and try to bump the width up so I have 20' inside.

I have never done that kind of drywalling (just minor repairs) or used one of those lifts. Do you think I could actually do a 14' x 50' wall myself successfully with one of those? How long might that take?

And I have been working with the local authority, they are the ones that told me about the measurements and requirement for fire barrier. Its different groups that handle the zoning, plan review, inspection - it's a real PITA to go back and forth to work out a solution with them. They seem to want me to submit final plans and then revise - which will cost me more money for engineering/updated drawings with every revision.

 

[readhead]

Check with the building department. With what you are describing the fire rated drywall would be installed on the outside of the garage in my location. Don't assume that it will be installed inside.

 

[Hayden]

Check with the building department. With what you are describing the fire rated drywall would be installed on the outside of the garage in my location. Don't assume that it will be installed inside.

Ok - that's what my designer was proposing with it outside the studs but under the sheathing and stucco. He made it sound like an option vs. a requirement but maybe I misinterpreted. I'll find out.

 

[turbowoodworker]

You are in AZ. Not sure of location, or HOA requirements but have you thought of a typical AZ flat roof, no eaves? Check out some of the nice AZ threads (Rattlesnake Or Ernies comes to mind). Problem if garage roof style must match house.

 

[turbowoodworker]

And always insulate and drywall!

 

[dcg9381]

I don't drywall.. Period. Or masonry.
The other option (perhaps) is that you do James Hardie "stucco" sheets if this meets fire code per your spec?

 

[kwb]

Attach it drywall the attached section if not more. The space inside will be far more useful than space between buildings.

As noted drywaller and installation will be cheaper than any exterior treatment unless you were planning T1-11 and the siding was the sheeting. Even then you don't have to do as much framing or sheeting so savings there. Tear off house siding and apply drywall to that surface.

 

[Hayden]

I haven't posted in a while but the fire code issue ended up not being a big deal. I just have to drywall a small section of wall inside with 5/8 and I had to get a fire rated door.

I ended up with a 20'x51' building (19'x50' inside) with a 15'5" ceiling and a 14' high x 15' wide door.

I am struggling to post pics through the forum. It keeps crashing my browser.

 

[CraigStu]

Good news. Thanks for the update.

 

[Hayden]

Good lord its hard to post pics to this forum. Is this a common problem? Here's 1 of a lot since I can't get anything posted without my browser crashing every. single. time.

 

[Hayden]

Back/side view.

Next on to electric, drywall, roofing, and eventually something on the concrete.

 

[NUTTSGT]

If your images are too big to get attached, you'll have issues. Once they are attached, you can link them here so you can see the "real" picture.


Hang on let me try to help you out.


EDIT: How's that ?

 

[NUTTSGT]

It's been awhile since you started this thread, like months. I didn't realize it had been that long.

As a refresher, you keeping an RV in this space ?

 

[acer66]

I never had an issue to upload picture here, prevents also dead image links.

Happy to hear that you were able to sort things out op.

 

[Hayden]

NUTTSGT Thanks for fixing my pictures. I figured out how to make them smaller (and switch browers) to get them uploaded but I hadn't gotten as far as making the full picture show up.

No I'm not parking an RV in there. With the shape of my lot it was the only real shape that worked. I went ahead and built it tall enough for a Class A RV or big toyhauler for resale value because those are very common where I live.

I have a boat that's 25' long x 10.5' high on the trailer and then the rest of it will be workshop space. I've got a bendpak 4 post lift and an old Mustang that needs a lot of work. I also do some woodwork once in a while.

 

[nadogail]

When Robert Burns wrote of the plans of Mice and Men, he really got it right.

 

[Hayden]

When Robert Burns wrote of the plans of Mice and Men, he really got it right.

I’m not sure which part you’re referring to but I’m just happy the damn thing is getting built finally.

I think you need to change your signature line for the new COVID era...I have found that you only get to pick one now. What a year.

 

[scottydosnntkno]

Thanks. That drywall is probably the nicest option, it just adds a lot to the budget.

It must be detached by some amount, there are a few windows on the house wall on the garage side.

Cooling would be quite a bit more I think. It's going to have 14x14 and 8x9 garage doors on the ends so it's never going to be real tight. My electric bill currently goes up by about $220 in the summer months and that is to cool a well insulated house about twice the sf but significantly shorter than the 14' garage.

I see you're a senior member so maybe you can help - I seem to have posted this thread twice but I can't figure out how to delete one. Do you know how?

I hope your budget is realistic because a little drywall is not going to add much cost at all. Especially just on a wall and not a ceiling.

25’ long x 18’ tall (being generous for height here) is 450ft or about 14 8’ sheets. I can get level four drywall in a entire new house For 1.30-1.70 depending on the layout. You should easily be able to get that small job for $2/ft or less,finished, or less than $1000 total. Just firetaped would be even cheaper. My guys would do that in about two hours start to finish hanging to fire taping.

Couple hundred for some insulation and you should still be about a grand total. Not a ton of money when your building a 50’ rv garage IMO

 

[johnnyradiant]

Fire barrier addition before pounding nails or at least while still framing generally isn't too big of a deal in the total scheme.

The closeness of the buildings triggered the additional fire barrier - I'm curious would not the whole occupied space then need to be covered with something (not necessarrily fire rated board) and not just covering the required fire rated portion? I'm pretty sure that would be the case here. It's been awhile since spending a ton of time in the code except for specific cases as they arise that I need a refresher on, and I have not yet encountered your scenario.

I remember going into a building years ago to paint it out and they missed a fire rated section while framing and boarding. The after the fact fix met the code aspect and the cheap and fast categories but the good category - not so much.

 

[Hayden]

The city ended up saying I just needed interior drywall and a fire rated door since there is a door that faces the house. Both sides are stucco which provides some protection as well.

 

[Mikea57]

Just curious... Could you bump out the width of the shop when it gets past the house? Say the back 25'?

EDIT: NM. I see that it's already set on stone... so to speak!

 

[Hayden]

Fire barrier addition before pounding nails or at least while still framing generally isn't too big of a deal in the total scheme.

The closeness of the buildings triggered the additional fire barrier - I'm curious would not the whole occupied space then need to be covered with something (not necessarrily fire rated board) and not just covering the required fire rated portion? I'm pretty sure that would be the case here. It's been awhile since spending a ton of time in the code except for specific cases as they arise that I need a refresher on, and I have not yet encountered your scenario.

I remember going into a building years ago to paint it out and they missed a fire rated section while framing and boarding. The after the fact fix met the code aspect and the cheap and fast categories but the good category - not so much.

The city approved it as just the adjacent section. It was actually their idea. I decided I'm going to drywall the entire inside with 5/8" drywall so it should be fine now.

 

[Hayden]

Just curious... Could you bump out the width of the shop when it gets past the house? Say the back 25'?

EDIT: NM. I see that it's already set on stone... so to speak!

Per zoning, yes. Per wife, NO.

 

[MushCreek]

Building codes are funny. The walls of my house have 8" of concrete, but they still made me do 5/8 FireX on the common wall. I just did the whole garage in FireX. It wasn't that much more money.

I insulated our attached one car. It makes a big difference when you hop in the car on a cold morning, and it's 45 in the garage instead of 20 like outside.

 

[Hayden]

Building codes are funny. The walls of my house have 8" of concrete, but they still made me do 5/8 FireX on the common wall. I just did the whole garage in FireX. It wasn't that much more money.

I insulated our attached one car. It makes a big difference when you hop in the car on a cold morning, and it's 45 in the garage instead of 20 like outside.

I got a smoking deal on wall insulation at Lowe’s so I’m going to go ahead with insulating now too. I did radiant barrier roof decking since it was about the same price as standard osb & I got the cheaper polystyrene insulated garage doors.
I have the opposite problem from you (hot) but hoping it’ll stay 100 instead of 110+, we’ll see.

 

[MushCreek]

We get hot, too. I find that attic insulation is particularly effective for heat control.