Wet Floor

[Stephen drew]

Just about finished with my pompeii oven. Built a block enclosure around the oven covered with slate tiles. For the roof I poured a 3 inch slab on top covered with epoxy paint. Druing the last rain storm the floor became wet. Water probably went down the sides of the chimney which was not caulked in time for the storm. I can't seem to get it dry. I have left a fan running 24/7for 10 days and have had numerous fires and it is still damp. You can even see steam rising from the floor bricks as the fire heats up. Even with a large fire the floor temp only goes up to 200 degrees or so when the top of the dome can be 700-900 dgrees. it only seems that the floor bricks are damp not the wall bricks. I worry that the insulation board under the floor is also wet and may just never dry. Any suggestions?

[Lburou]

Re: Wet Floor

The way you describe it, there seems little doubt that the floor insulation is not dry....Only multiple, long duration firings will dry it out.

[RTflorida]

Re: Wet Floor

Sorry to say, I have been down this road. It took 2 weeks of daily fires with duration times of 5 - 8 hrs each. The first 3 days were a battle to just keep any kind of fire going. I actually had water weaping (continuous drip) from all 4 sides of my hearth support slab, for the entire fist week.
Hang in there and keep building long duration fires...it WILL slowly get better day by day.

RT

[david s]

Re: Wet Floor

Allowing some time (say 4-5 days) after firing will allow some of the moisture to migrate to the drier parts of the oven, then you can go and fire again. This takes more time of course, but saves on fuel and firing time in the long run.

[Tman1]

Re: Wet Floor

Can you lift some of the floor pieces to allow more air to get/under them to help dry the insulation board? I concur that without direct access, this will be a longer process to rectify.

... and get that joint sealed!!

[Neil2]

Re: Wet Floor

Did your build possibly leave a "bathtub" in your structural slab that is holding water ?

In a worse case scenario, you may have to drill up through your structural slab to provide drainage.

For those just starting, it is advisable to make sure your structural slab slopes slightly away from the middle to ensure positive drainage. Water will always find a way in. Trying to make a WFO 100% waterproof is frustrating and probably fruitless.

[david s]

Re: Wet Floor

For those just starting, it is advisable to make sure your structural slab slopes slightly away from the middle to ensure positive drainage.

Agree wholehartedly, I always try to do this, it is an important design consideration.

[Stephen drew]

Re: Wet Floor

Thanks to all for some really good suggestions. If I can't get it dry soon I might take up a few floor bricks to see if that helps. Funny, but the area directly beneath the fire seems to be the slowest to dry so I have been moving it around. Has anyone actually drilled a hole through the slab for drainage? Seems like a good idea just in case. Any downside to doing this? Thanks again.

[david s]

Re: Wet Floor

If you drill some holes in the bottom of the slab, glue some insect screen over them to prevent the entry of uninvited intruders.

[Neil2]

Re: Wet Floor

"glue some insect screen over them to prevent the entry of uninvited intruders."

The holes could be as small as 3/8 inch dia. Two or three holes should be plenty. You could screen them as David suggests, or widen the start of the hole a bit to insert these:

[tmarsala]

Re: Wet Floor

Ah yes-been through this one as well! I thought I had waterproofed well, but on a week-long storm there just is no such thing. Yes-the insulation under the floor gets wet. It took about two weeks of continual fireings to get it back, but DON't WORRY! It will dry!!

Meanwhile, enjoy the fires and the steam!

Tom

[Stephen drew]

Re: Wet Floor

Thanks again for all the suggestions. My oven is finally dry and I am getting floor temps up to 850 degrees. It took numerous hot fires over a three week period.

[Neil2]

Re: Wet Floor

Good news Stephen.

I end up going thru the same process every spring. It is a way to get rid of dead fall branches and pruning from the spring yard cleanup.

[DaVince]

Re: Wet Floor

Hi all,

I finished curing my oven, used it once, then 3 quite heavy storms in one week made me end up in the same situation as described here. I'd like to know if I should gradualy fire it up to prevent damage to the floor. Or is this of lesser importance here?