# Concrete prices for workshop. Average?



## Chris (Sep 15, 2003)

Well, I have been getting prices on pouring slab in 1/2 of existing covered cypress workshop that currently has gravel/dirt floor. Dimensions inside barn to be concreted in are 18' deep by 20' wide. I want to pour a 10' landing pad with grade outfront so total is 28x20 roughly. (Probably less considering framing etc) Looking at about 6.5cu yards. Can purchase locally minimum of 6+ without any surcharge or penalty.

Price for 3500# psi + fiber mesh = $67.50 per yard = $438.75 + tax. or about $475.00 total for concrete. (This was best price as other places were as much as $15-20 per yard higher with minimum 8yr loads) 

Got a guy that will help with framing (I have all PT 2x6s etc and stakes needed for framing) and do the finish work for about $300.00 total. So for less than $1K I could possibly have it done?
I will try to do all of the dig work with my box scraper/blade but I am sure it will be a task. Any additional problems with pouring/finishing slab that is under roof? (will take longer to cure and set I guess) 

Any opinions on the cost, ideas on construction or any other helpful tips for this project? 500 sq feet is not huge, but better than working on the rough dirt gravel surface.  

Thanks.


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## Chris (Sep 15, 2003)

*QUESTIONS*

One more thing.

Framing ?s:
1.
Was going to use 2x6s and attach them to existing poles 
in barn to form frame inside of workshop. Will this work? 

2.
Was thinking about then leaving them in place to provide a protective barrier from the cypress boards to the ground. (currently exterior vertical cypress boards do not touch the ground) Any problem leaving the frame in place?

3.
Also, I could just cut the frame down outside (reciprocating saw)
on the landing pad and leave it in place or remove it and backfill with gravel etc? 

4. What about expansion joint on slab? What to use for this and where to place it?

5. Is 4" depth suitable with 3500# and fiber mesh? Standard workshop usage etc. 

Thanks
Andy


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## balmoralboy (May 22, 2004)

*Re: QUESTIONS*



> _Originally posted by admin _
> *One more thing.
> 
> Framing ?s:
> ...


Andy,

My general comments on concrete floors - I've laid about 100,000 SF in a former life so I won't be offended if you don't take my advice. Plenty of others have made that mistake before you!

No problem pouring floors inside. It's actually better because the floor doesn't get overheated or dried out by sun exposure. Also if it rains you don't get drop marks. But think hard about how you're going to get the concrete over to the back corner. A couple of big 20 yr olds with a wheelbarrow is a good choice for a floor that size.

Will you be heating the shop? If so, the best way is probably to go in-floor. You can lay the tubing for a floor that size for about $200. Just stake it into the ground with heavy wire.

Do you have any drainage built in? Are you going to pressure wash any of those rebuild jobs you do before you start in? You may want to slope the floor to the door - to help you design the slopes, NOBODY is good enough to hold a concrete floor better than 3/16 inch to the foot flatness - if you go 1/8"per foot you will get puddles if you wash the floor. At 3/16 you can get a floor that drains dry. 

That brings up another point - use a laser level to set the grades, but set up markers that are outside your floor, and thus will still be there to measure by. Nothing makes me more savage than a floor finisher who pounds stakes in the middle of the floor with the level marked on them, and then knocks them out when he gets the concrete into that area. Presumably so he can ignore the level you want!

Also, make sure you put a vapour barrier under the slab. 

Have you thought about floor finish? Smooth looks nice but can be slippery when it gets oil on it. I'd go with a fine broom finish - like simple john put on his walkway slab. It is fine enough to clean easily, but coarse enough to give you a grip. I wouldn't bother using a floor hardener but a curing compound will keep the dust down. 

1. What is the frame for? Is it to hold the edge of the slab? Or will it become the sills for the wall?

2. If the 2x6 is going to be exposed to the soil, I would use cypress or some other species that is rot resistant (or pressure treated if you don't mind poisoning your land). I would also tend to put some kind of plastic barrier between the frame and your wall boards so the rot doesn't travel up the wall. Around here we call that a sill gasket. Another option is to use the slab as a foundation and frame up from it. If so, set a 2x4 on the flat into your slab to give you something to nail to.

3. I don't understand "cut the frame down outside (reciprocating saw) on the landing pad and leave it in place" Are we talking about removing a wooden frame used as a form for the edge of the slab? If so, cut it out or leave it is a question of what you think looks better.

4. With 3500psi concrete and glass fiber (when you say fiber mesh you really mean loose glass fiber mixed in, right?) you shouldn't need any expansion joints in the slab. I used to do floors with 36 feet between joints, and that was using steel mesh, not the fibre. The fibre distributes your tension capacity throughout the slab, so cracks are much less likely.

5. 4" thickness is fine, unless your soil is very soft, or you're planning to get a steel wheeled tractor on it.

Sounds like a great workshop. I'm jealous!


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## Chris (Sep 15, 2003)

*Re: Re: QUESTIONS*



> _Originally posted by balmoralboy _
> *Andy,
> 
> My general comments on concrete floors - I've laid about 100,000 SF in a former life so I won't be offended if you don't take my advice. Plenty of others have made that mistake before you!
> ...


Great info from someone who has been around the block and probably poured it too! 

Responses:
1. I haven't thought about getting concrete to back corners. About how far can a concrete truck (ready-mix) pour off? I have a door that might work that will be just on the other side of the slab. Will think about this. 

2. Fine broom finish will be great. Offer some traction and still look ok. 

3. What is a curing compound? Like a concrete sealer of sorts?

4. Frame is there to hold the edge of the slab. The frame would be set and at 4" pour would extend 1.5" above poured slab to provide a little "lip" to the slab for extra protection from the elements etc for the workshop.

5. Nope -- no heat in here. I am in Louisiana not Nova Scotia! 

6. I will work on the slope. Was thinking at least 3/16" per foot would work. It might be a fun task to get all of this right. Wow. 

7. Great no expansion joints with 3500 and fiber mesh. Goodie.


Thanks so much!
Andy


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## Chris (Sep 15, 2003)

*ONE MORE THING? HOW ABOUT THE PRICES? ARE THEY GOOD FOR THE WORK/MATERIALS ETC I HAVE DESCRIBED?*

Thanks
Andy


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## Chris (Sep 15, 2003)

Anyone have any additional input?


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## RockyJSquirrel (Jun 6, 2004)

I have a similar project underway but I'm letting my neighbor handle the slab since he works for a local concrete plant. Mine started out as a shed but morphed into a 12'X16' building with water, power and a peaked, shingled roof complete with ridge vent. I built it on 4X4 poles with the idea that I would pour the floor afterwards. 

Hopefully your prices are still good. We have a 'concrete shortage' right now, seems like Chine is building another huge wall or something and it's affecting availability worldwide.


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## balmoralboy (May 22, 2004)

*Re: Re: Re: QUESTIONS*



> _Originally posted by admin _
> *
> Responses:
> 1. I haven't thought about getting concrete to back corners. About how far can a concrete truck (ready-mix) pour off? I have a door that might work that will be just on the other side of the slab. Will think about this. *


* 

Usually it needs to be quite a good slope for the chutes to carry. I've seen long ones but they were down from a second floor truck yard. aside from that i've always used pumps. On my floor here - basement apartment pouring over the infloor heat we used two guys on wheeling with the chute coming down the outside stairs. for 1500SF 1.5" thick




2. Fine broom finish will be great. Offer some traction and still look ok. 

Click to expand...

Show your finisher Simplejohn's slab - nothing like a picture to get the message across. After all, once it's set that's the finish you're going to live with.




3. What is a curing compound? Like a concrete sealer of sorts?

Click to expand...

Same as a concrete sealer - every snake oil salesman has a different name for it. Technically, a sealer can go on at any time and is just a paint. A curing compound is supposed to interact with the concrete on the surface and is sprayed on just after you float the surface. A hardener comes in granules and is shaken over the surface and then floated in.




4. Frame is there to hold the edge of the slab. The frame would be set and at 4" pour would extend 1.5" above poured slab to provide a little "lip" to the slab for extra protection from the elements etc for the workshop.

Click to expand...

 Consider using the top edge of your frame as your level. It's easier to work your screed across rather than trying to bump up against a wall. You'll get a pretty rough edge with a lip and also small unfilled holes against the frame. The tradeoff is it may be more expensive or harder to frame up to your walls, but a floor that runs hard to the walls without a crack is worth a lot. If you really need a lip, consider coving the wall to floor edge, but that makes holding your levels a lot harder. For your first project, that's probably too difficult.

Thinking about it as I edit, you may save enough on the smaller forming wood to pay for the extra framing wood. 




5. Nope -- no heat in here. I am in Louisiana not Nova Scotia! 

Click to expand...

 Sometimes you gotta ask, even when you think you know the answer!



6. I will work on the slope. Was thinking at least 3/16" per foot would work. It might be a fun task to get all of this right. Wow.

Click to expand...

 Don't go too steep. 1/4" is too much and you'll always be tripping.



7. Great no expansion joints with 3500 and fiber mesh. Goodie.


Thanks so much!
Andy

Click to expand...

*Glad I could help. Most of the plants are shut down now. Nice to think all those hours i put in can help somebody!


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## waynl (Jun 2, 2004)

Your prices sound pretty good here in NW NJ. Last I heard concrete was about $75/yd with a 5 yd min.

I personally like a smooth finish, much easier to keep clean. as for being slippery when oily, that's what Speedy-Dri is for.

And the 4" depth is fine unless you have a large tractor to bring into the shop. Then I would make the edge 6" thick to about a foot in from the perimeter to prevent beakoff. Make sure the soil/gravel underneath is compacted and/or firm.

My brother-in-law built himself a shop two years ago in NE PA. 30X50 floating slab w/conventional 2x4 framing on top. We poured that floor on about the worst possible day we could find, 20 degrees with a NW wind at 40MPH and snow flurries. That mud did not set up for finishing for almost 24 hrs, then we had to sprinkle it with hot water to get a good finish. Today it looks great. He painted it with an epoxy type coating, I think.


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## Chris (Sep 15, 2003)

I have more questions on the framing of the slab. 

What is the preferred way to dig out the dirt for this slab? Will my 8N with a box scraper/blade work ok or should I rent a better tool or hire someone for the job? What are the proper steps for framing a slab? I have a feeling that with the existing slab behind it and the walls on the side, it might kinda difficult to get everything dugout in good order. It sounds like it is going to take quite some time to prep. Wonder how much it would cost someone to come and prep?

Thanks for all/any additional input on this.
Andy


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## Stewart (Sep 17, 2003)

Andy,

The posts on SJ's project should cover about everything. BB's posts are full of good information as well. If you can save that much money by doing it yourself that is great. I don't see why you couldn't use the Ford to do the dirt work. You can do it with a shovel and rake if necessary. Getting the site prepped right is the most important part. Were you planning in using a plate compactor or one of those hopping compactors? :truth:


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