# Fire Pit on Gravel



## unclenanoose (Jun 11, 2010)

This is my first time on the forum, and I am new to DIY, so please forgive me for any dumb questions.

I am planning a wood burning square fire pit...interior dimensions of approximately 3' x 3', and height approx 22". It will be sitting in an 16' x 16' area that is about 18"-22" of 3/4"-1" gravel (I will eventually put seating in there around the fire pit). There is a 4" perferated drain pipe under the location for the pit (about12" under the gravel) and leads downhill to outside the fire pit area. I have stone for face of the firepit, and firebrick for the interior.

Here are some of my plans, and questions regarding them. Please feel free to advise on if you think my plans are a bad idea or have better.


4'x4' concrete 4" base for the FB and stone face. I will recess this to be flush with the gravel surrounding it. Would it be better to do a solid slab, and then line the entire botton with FB, or leave the middle open for drainage and just a gravel "floor"? My question with leaving the gravel floor is once I have ash in the firepit, will it just make mud and prevent drainage later or, or wil the ash eventually make its way to down to the drain and plug it up?
If best to do the full slab, should I leave some gaps on the first one or two layers of the FB walls and face stone for drainage?
I am planning on using Heatstop II mortar for the FB. If I do the full slab and line the floor with FB, should I still mortar the FB on the floor?
Should I leave a gap (couple of inches and then fill with mortar) between the face stones and FB, or mortar the face stones directly to the FB?
Should I use Heatstop mortar on the face stone and capstone, or common mortar on everything but the FB? My wife wants a drystacked look, but with the stability of face stones adhered together if possible.
At a height of 22", should I build in venting holes around the bottom to allow more air to get to the fire? If so, any ideas of how to get the best size hole all the way from the interior through the FB, mortar and face stone?
I know that is a lot of questions, but I appreciate any of your input!


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## Allison1888 (Mar 16, 2008)

Before you get started, have you checked with your building dept. to see if outdoor wooden fire pits are allowed. Our town and several surrounding have cracked down on them for safety reasons (although I still love them!). Unfortunately, I can't help with the technical questions, but thought I'd toss that out first.


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## jomama45 (Nov 13, 2008)

unclenanoose said:


> This is my first time on the forum, and I am new to DIY, so please forgive me for any dumb questions.
> 
> I am planning a wood burning square fire pit...interior dimensions of approximately 3' x 3', and height approx 22". It will be sitting in an 16' x 16' area that is about 18"-22" of 3/4"-1" gravel (I will eventually put seating in there around the fire pit). There is a 4" perferated drain pipe under the location for the pit (about12" under the gravel) and leads downhill to outside the fire pit area. I have stone for face of the firepit, and firebrick for the interior.
> 
> ...


I actually just set-up a patio with a firepit built in. I'll try to take some photo's on Monday of the initial process.


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## unclenanoose (Jun 11, 2010)

Thanks for the tip on the question, Allison. We are good here, as I can't find any regs against it, other than occasional regional burn bans during drought weather.

Thanks for you input and answers, jomama. We are planning to use the same cap material as the veneer stone. I'd love to see some of your pictures. 

Thanks again for the responses....It's nice to have people to bounce ideas off of.


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## jomama45 (Nov 13, 2008)

jomama45 said:


> I actually just set-up a patio with a firepit built in. I'll try to take some photo's on Monday of the initial process.


 
As promised, the first few pics, I'll follow up with more after it stops raining & we get a chance to pour............

























BTW, I guess I should explain what you're looking at:

- Built the inside form in the shop out of 1/4" Masonite/hardboard, wrapped around 3 OSB circular discs/cut-outs. The top 3.5" is a smaller dia. so that when it is stripped out, it will allow for an overhang for the firebrick laid inside of the pit.

- There are probably about 10 - 2" screws sticking out of the bottom of the cylander/form you see. The last time we were on the job, we simply mixed & poured 4-5 bags of Quikcrete into the hole we dug, lowered the FP form into it slightly, leveled & adjusted the form where it needed to be. Now that the concrete is set, we don't need to worry about adjusting the form when pouring, or worry about it moving around on us.

- There is a 2" EMT conduit bent to a 90 degree angle, coming into the form about 4" from the bottom for a fresh air intake. On this one, we really didn't have the topography to run a drain to daylight. The HO realizes that water will be an issue at times, but will probably make some kind of cover for himself.


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## unclenanoose (Jun 11, 2010)

That's going to look great....can't wait to see the finished product!


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## jomama45 (Nov 13, 2008)

Finally got the chance to take final pics:


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## hbarraco (Oct 26, 2010)

*Concrete fire pit*

Looks great! I'm considering doing same and have good info from your experience. One question; Is the top of the concrete surrounding the hole FB also and/or does it need to be as well?
Thank you!


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## jomama45 (Nov 13, 2008)

hbarraco said:


> Looks great! I'm considering doing same and have good info from your experience. One question; Is the top of the concrete surrounding the hole FB also and/or does it need to be as well?
> Thank you!


Thank you.

The top is entirely concrete, and it returns down about 4", the thickness of the slab. It also overhangs the FB by about 3/4" , which is merely for logistical & asthetic reasons.

I've never had a problem with concrete here before, BUT you have to watch the circumfirance and the depth of the pit, as well as the intensity of the fire. I've checked these in the past with an infared thrmometer, and have no reservations of exposing concrete at the top with the right dimensions in the firepit.


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