Garage remodeling/re-construction after fire...

[daft_mx5]

Hi folks, sure happy I found the forum! Looked at some of the projects and found true inspiration...

To make a long story short, had an electrical fire about a month ago in my detached garage. Everyone is okay and everything is replaceable, but the fire also took my baby, a 300+hp Miata which was an AutoX/track toy I've had for years. That's definitely the worst part.

Well I've decided to take a cash buyout from the insurance company and act as GC for the remodeling/re-construction of the garage so that I can make it like I want. Basically going to strive for a really bright and clean, and somewhat minimalist garage. I'll probably use this thread as a build diary type thing.

Structurally, everything is sound, as the structure was not affected by the fire at all. It's pretty much all cosmetic smoke damage and a single blown out window and frame. A few tires caught on fire so the entire garage is coated in black nasty soot.

It's a single story (with attic) 22x35 garage, so actually a nice size. It's slab floor and footings with a 2 layer block foundation on top of the footings.

I've got a crew coming in to strip it down to the structure and then another to come paint it with that special smoke/smell inhibitant paint.

After that I have to decide to what to do with the flooring.
Like mentionned it is a slab floor, approximately 2.5-3 inches deep of concrete, but the entire floor has been covered for years by a subfloor made of strapping, 1" rigid foam and then TWO layers of 5/8 inch OSB Tapconned in... Previous owner did it for warmth because of the Northern climate. I took a section off and the slab is in decent condition, but with minimal pitting and chipping. I basically want the slab to look nice (polished or epoxied) and be strong enough for one of those movable 4 post lifts like the Directlift pro park 8 or a scissor lift. Is the existing floor a candidate for these requirements?
I got a couple quotes done for re & re with a thicker slab and polished and nearly had a heart attack at the prices. Are there any other options I should be exploring?



Thanks,

Phil

 

[Stuart in MN]

Sorry to hear about the bad luck, but it's good you're recovering. Are you sure on the thickness of the floor? That sounds pretty thin for a typical garage floor. If you're going to finish it off with some sort of coating, I suppose you could drill a few small holes here and there to check the actual thickness and then patch them before the finish goes down.

 

[Kevin54]

 

[Bull]

How did the fire start?

 

[rburke65]

Welcome daft mx5! Most lifts require the typical 4" of concrete. Your garage is 770 sq. ft. of floor space which is less than 8 yards of concrete to replace the floor. If you are already questioning the floor at this stage of the rebuild, just re-do it. At least you would be sure of what was under your lift. Can you or your friends pour or place the concrete......Shouldn't be that big of a job. I think you will be happier in the long run. Just my opinion. Good luck....RB

 

[daft_mx5]

Thanks guys, definitely going to drill a few holes to see what the actual thickness is...

Bull, the fire marshall and the insurance company investigator determined it started when the ballast from an old fluorescent light blew. Sparks caught on a piece of carpet that was on the floor and took off from there.

 

[Bull]

Wow...it's scary to think that something so random like and exploding ballast and some carpet can cause a fire like that. Makes me more paranoid than I already am.

 

[daft_mx5]

Well finally uploaded some pics, here it is as it stands right now. Work to clear contents will hopefully start next week...

 

[JohnK007]

Damn, those photos bring back some unhappy memories In 1992 my house was struck by lightening. It followed the antenna wire from the chimney to the basement where it started to burn. Like you, the fire damage was minimal but the smoke and water dammage substantial. It took over 4 months to recover. What a mess!

I suggest you get everything out of that garage asap. Rent or buy a pressure water and spray down your tools, that vise, and anything else that can be cleaned and saved. Don't be surprised if the chemicals and acids in the smoke permanently etch some metals. Some react badly, some don't, but the sooner that soot gets off stuff you want to save, the better. Then start pulling that drywall, get rid of all the insulation, and wash the **** out of the floor. My house was sprayed with that smoke inhibitor stuff Can't remember the name of it but it looks like a heavy primer. It worked OK but you would still smell smoke now and again. It's definitely worth doing.

Man, I don't envy you. You have a long, dirty road ahead. But on the bright side, you can get things the way you want them. Good luck!

 

[daft_mx5]

Two crew days and four 20 yard bins later, contents are all gone and the interior is almost stripped. All that is left to do for the inside is remove the back shop wall and the subfloor.

 

[Chris Adams]

When my garage burned (lost my customized Bronco, and a lot of skin) the melting tires soaked into the concrete. The concrete was never replaced as it was still structurally sound, but those tire stains were there when I sold the place three years later. I'm sure they are still there.

Heat rises, most things down low are not really damaged in a quick fire like that.

You may want to coat/cover your floor but I suspect it won't be truly damaged.

 

[daft_mx5]

Subfloor came out, was not fun. Slab is pretty poopy, no huge cracks but some easy chipping and soft spots. And it does not seem very thick at all, especially on the edges near the footings. Seems like it may have just been poured over compacted dirt/sand?

Been getting quotes for removing and replacing the slab, and it's pretty depressing. Cheapest yet is 8000$...

 

[daft_mx5]

Here's a few pics after being painted with the special smoke damage paint...

 

[Motown 454]

Too bad its cracked maybe you could have overlaid it with 3" and a concrete adhesion promoter. If you could afford to lose the height.

 

[pcmeiners]

Likely late,as to smoke smell....
My mom's house went up in 1996, entire basement gutted, entire interior covered with black soot, smell was really bad. Someone told me use acetic acid or vinegar. Sprayed (soaked) all beams, walls, floors with vinegar, believe watered down 2:1, took 60 gallons purchased at food store (white vineger). After spraying with charcoal paint mask, (as the acetic acid smell is tough), closed building left for a couple weeks, opened windows aired out for a another two weeks, upon return very little smoke or acetic smell, 3 months later during renovation no smell, fantastic. Applied with a pressure sprayer, also removed charcoal from beams with pressure sprayer (3000-3500 lb psi unit) with head close to wood, before applying vinegar; (must have had a few hundred pounds of charcoal). Had tried expensive commercial oder removers which helped slightly.
The person who told me had placed large trays in each room full of straight vinegar for a month, let evaporate, worked also. In either case the envelope needs to be somewhat sealed (all windows were busted out, but covered with plywood), vapor tight not necessary but tighter the better.

 

[ddawg16]

Well, I'm not going to say "sorry for the loss" (except for the car...so sorry about that)....instead, I think you are kind of lucky....you had insurance....and since your being the GC....you can put her back better than ever with little or no extra cost.

I guess it would be too nosey to ask how much the insurance company gave you for the damage......

It sounds like you have a good handle to getting rid of the smoke smell and damage.....

No doubt you are going to fully insulate the walls? I would even do the one next to the house....keeps down the noise....

Start planning your wiring...good time to get it wired the way you want before the drywall goes up.

 

[daft_mx5]

Well, I'm not going to say "sorry for the loss" (except for the car...so sorry about that)....instead, I think you are kind of lucky....you had insurance....and since your being the GC....you can put her back better than ever with little or no extra cost.

I guess it would be too nosey to ask how much the insurance company gave you for the damage......

It sounds like you have a good handle to getting rid of the smoke smell and damage.....

No doubt you are going to fully insulate the walls? I would even do the one next to the house....keeps down the noise....

Start planning your wiring...good time to get it wired the way you want before the drywall goes up.

Thanks Ddawg, yeah other than the car, don't have too much pity...
Obviously the most important thing is that no one was hurt.


Phil

 

[daft_mx5]

Too bad its cracked maybe you could have overlaid it with 3" and a concrete adhesion promoter. If you could afford to lose the height.

Funny you should mention that. Had a fresh look at it and really, it isn't that bad. Was poured in 1971. There is really only one soft spot near the door , no frost heaving or shifting. The few cracks are surface.
Had a well known local concrete guy come in this morning and he said the slab is in quite good shape. Drilled a few pilot holes and the thinest was just a hair under 3" and is on gravel.
He said he could chip the soft spots and fill-in, then overlay 3" like you mentionned. There is enough room to spare, the overlay would just come up to the bottom of the base plate. He said wall electrical would need to be in before he started because he recommended using concrete board on the lower wall in case the overlay touches it.

He also mentionned the possibility of using Insul-tarp on top of the old slab, but I 'm not sure about that. Wouldn't it basically make the new slab foalting?

Definitely would like to put a MaxJax in there, but I don't know if that would be wise...are two bonded layers stong enough?

 

[Daniel Dudley]

Using insultarp is pretty common in these circumstances. He is more concerned about vapor than bonding. If you want to put in a lift, you will need to pour pads into holes cut into the current floor before you pour your new floor, and make sure your anchors go way down into the pads. Use the fiberstrand reinforced concrete for your slab. It may not give you a glass finish, but it is as strong as heck. Wire mesh is also good.

BTW, insultarp will act as a slipsheet between the floors, and should prevent cracks from transmitting up from the old slab, which they can do.

I would go with the guy that is telling you to do this. He knows what he is doing, and you can trust him. Tell him about your lift plans, and get specs. Or you could go for an all new slab, and do radiant, again prepping areas for the lift. Big bucks. I would maybe consider pouring the lift pads as part of the new floor, in one shot, but I would definitely make a grid of rebar reinforcing the new slab around those areas, about one inch above the old floor. These things will not add much to the cost of your cap, but they are well worth it.

BTW, I am a noob here, but I do a lot of odd concrete pours. I have seen open air decks made out of three inches of concrete, some wire mesh and rebar. Reinforced concrete is unbelievably strong.

 

[daft_mx5]

Hey Dan,

Good call on the pads.
So basically cut two sections out (4'x4'?) before the overlay, dig it down, rebar, put in new subgrade so that pad will be at least 8 inches deep?

 

[daft_mx5]

Been a busy few weeks.

-Roof was completely removed (2 layers of shingles + plywood) and replaced. Also had vents added.
-Siding, soffits, and sheathing were ripped off.
-Man door that used to be in front was covered and framed-in.
-Rough-in for larger 3x4' windows and new side man door done.

 

[daft_mx5]

New sheathing and house wrap. Also installed the new windows and man door, and the flashing and siding were started.
Congrete guy came in to secure the mesh as it will be in Friday. 2-3" bonded overlay with 5000psi and two 3x3 foot pads.
Happy everything is coming together!!

 

[daft_mx5]

New concrete slab overlay and pads are done!

They did a great job. Polished 5 times then two coats of 100% solids acrylic sealer.