Kiln Chamber Floor

[Sawmill_Nick]

Just ordered a new woodmizer dh4000 kiln today and I am trying to get started on designing and building the chamber.  The chamber will be a standalone building approximately 24' x 8' x 10' high.  I would like use concrete for the floor but have heard that this will lead to a difficult time in maintaining a proper temperature since the concrete will absorb heat. We do tend to get cold winters here in Michigan.  Is this a big problem?  If so could I build a false floor over the concrete and insulate using 2x4's?  Also, is it possible to insulate under the slab?
I am planning on using carts and end loading the kiln so therefore I don't want to make the floor a great deal above ground level and have to build up the tracks.  I'm sure plenty of people have used concrete for the floor and I'd like to hear your thoughts.

Nick

[Larry]

Poured my kiln slab last week.  I was a bit unsure of slab insulation so I talked with Tripp Lewis at Nyle.  We discussed at length insulation under the slab.  I was thinking it might be better to put insulation on top of the slab and cover it with plywood.  Ending up putting 1 1/2" of R5/inch under the slab.  I'm sure the recommendation would have been for more if I was in the frozen north.

Nyle also has some good plans for a kiln chamber.  Think they cost $50 but I'm thinking they were going to put them online for free.  Give Nyle a call with your questions...there good folks.

All I gotta do now is put up a few walls and start drying wood. ;D

[red oaks lumber]

congrats on the new purch. put 2" high density foam under your slab, also go down vertically on the outside perimiter 2' to keep frost from creeping in from the edges.
one bit of advice..  don't cut corners on insulation spend the money to do it right. you'll see come janurary just how hard it is to heat a space at 130 deg. when it's minus 25 deg. outside

[Sawmill_Nick]

Larry - The temps probably do get a little colder up here during the winter so I'll make sure I put the foam down first.  Good to see that your starting a kiln, are you using carts or side loading?

Red Oaks - I know the insulation is a little expensive but I want to do it right the first time.  How thick of a slab did you put on top of the 2" foam?

[scsmith42]

+1 on what Red Oaks Lumber said.

Re the thickness, your DH4000 is capable of drying 4000 bd ft of 4/4 oak.  That equals about 24,000 lbs of wood.  If you're forking in and out of the chamber, you're going to have a lot of weight on the forklift tires (or kiln cart wheels).

I would use 6" of concrete personally (with reinforcement), just due to the concentrated weight when loading.

[beenthere]

Search member Onewithwood for pics and thread of his kiln build including tracks. May give you some good ideas.

https://forestryforum.com/board/index.php/topic,1400.msg115066.html#msg115066

[Larry]

Plan is to use kiln carts on a steel track.  Watch eBay for the wheels.

My slab is 6" thick with 1/2" rebar.

[Sawmill_Nick]

Been busy with several projects so it's taken awhile to get this far.  Poured the slab just before thanksgiving and had to cover for a week due to the cold weather.  Just got the kiln framed and working on the siding now.





Hoping to get it all enclosed and insulated before monday.  I found a good deal on the foam insulation at the salvage yard so I should have just about everything I need.

Nick

[ATLGA]

What description should I look for on Ebay for the wheels?

[Larry]

V wheels in business and industrial.

[Den Socling]

McMaster-Carr has a lot of V-groove wheels. Single flange wheels will work also. V-groove, of course, use angle iron for tracks and single flange use flat stock. You might want to consider more than four to reduce wasted space under the cart and to distribute the weight. I use 34 four inch wheels under our smaller vac kilns.

[west penn]

   when using V groove casters   do the swivel casters want to bind when changing directions? Seems like they would want to swivel and bind up on the angle iron.

[ATLGA]

Thats a good question, I was also wondering if some of the wheels or internals would have issues with the heat and humidity.

[scsmith42]

I would stay away from any type of swivel caster.  Typically the v-groove casters ride along a track that you install on the kiln floor.

Before I built my track system, I used carts with swivel casters on one end, and straight casters on the other.  It was a monumental PITA to get the carts in and out - the track and v-groove casters solved the problem.

Nyle sells the proper casters for kiln carts, and their price was pretty competitive too.  They are greasable, and I have not had any problems with mine in 6+ years.  Plus, Nyle's support is so great that I like to support them back by purchasing from them.

[Den Socling]

When using V-groove, leave a little slop (1/4") at the axle between the wheel and the cart. Then the wheel can ride back and forth to correct for alignment problems.

I wouldn't buy anything that didn't have grease fittings but you find a wide variation in bearing problems. If you dry oak all of the time, you will need to grease bearings frequently. If you dry maple all the time, you can get by with a squirt a year.

[ATLGA]

I would stay away from any type of swivel caster.  Typically the v-groove casters ride along a track that you install on the kiln floor.

Before I built my track system, I used carts with swivel casters on one end, and straight casters on the other.  It was a monumental PITA to get the carts in and out - the track and v-groove casters solved the problem.

Nyle sells the proper casters for kiln carts, and their price was pretty competitive too.  They are greasable, and I have not had any problems with mine in 6+ years.  Plus, Nyle's support is so great that I like to support them back by purchasing from them.

That makes a lot of sense to me. Ill be calling Don this week to place an order. Ive spoken with him a few times and he has always been very helpful and professional. I need a couple other things too that they have so I can knock it all out with one call.