Air Drying on Pallet Racks

[Tom the Sawyer]

Your thoughts are appreciated...

To conserve space around my mill area, I am planning to use pallet racking for air/pre-drying before going in the kiln.  12' tall pallet rack uprights on concrete post piers would let me store 3 or 4 lifts of lumber for each section.  I intend to put a metal shed type roof with a 2' overhang over the racks.  To prevent degrade from moisture or sunlight, I plan to hang shade cloth from the overhangs.  If anyone has done something similar, what level of shade cloth gives adequate sunlight protection and yet permits sufficient air flow?

[scsmith42]

Tom, I store lumber in my shop on 14' lengths of pallet racking and I had to add 1/4" plate to the sides of all of the horizontal supports to kerf them from bowing under the weight.

You might be ok with shorter widths but check them for sag.

[Tom the Sawyer]

Scott,

I considered that possibility when I was figuring this out, and I'll be watching for it.  My current pallet racking beams are 9' long and 4" tall.  My kiln is designed for lengths up to 12'6".  The widest portions of the drying racks, the beams will be 13' long and 6" tall.  Each lift should have 5-700 bf, 3-4000 lbs., (my forklift is not as beefy as yours  ;)).

I build my own stacking pallets, they are 2x6s on 16" centers, 8' and 12' long.  Each pallet would sit on its own pair of beams.  The 13' beams are only $35 each, the 9' are $20.  A drying shed isn't currently in the plans so I am hoping that the shade cloth will make for a suitable environment.

[YellowHammer]

When I air dry, I like to keep as much weight as possible on the stacks, generally 2 to 3 units of stickered wood on top of each other, providing significant weight and noticeably helping the lower stacks to stay straight, flat and compressed. 

My concern with stacking individual pallets on shelves for air drying is that you will not have any weight on top of them and will see more degrade than if you stacked them one on top of the other in the same space.

As far as shadecloth, I've never used it, but some species will need extra airflow such as fans, while others may benefit from reduced air flow, like white oak.  Each species has a different drying behavior and forgiveness, so stack placement, wind and other environmental factors should be a consideration for different species. 

[OutlawB52]

Can someone post some pictures of their air drying pallet rack system ? I need to expand and they are fairly inexpensive in my area for what they are . Also , do you pour concrete pads underneath them ?  Thanks, Rod

[Tom the Sawyer]

Funny that you should mention that.

Got my concrete pad poured about 3 weeks ago - had to let it set up to get strong.  My pallet rack came in yesterday and my wife I had it put up within a couple of hours.  Still need to put a roof on it, shade cloth draping, and start filling it up.  The uprights are 10' high, the orange sections are 9' long (for 8' lumber)and the green section is 13' long.


 

[OutlawB52]

Nice . Post the tin roof when it's up . Thanks

[scsmith42]

Looking good Tom.  Thanks for the pix and update.

[OutlawB52]

Hi Tom , are you going "condo" and placing  a third stack on top ? 

[YellowHammer]

Nice

[Tom the Sawyer]

Outlaw B52, 

There will be a sloping metal roof on top of the racks (metal is supposed to be cut and ready to pick up this week).  The roof structure will overhang the racks by one foot and there will be shade cloth drapes hanging from the roof frame, all of the way around.  My forklift only lifts to 8' above ground level so no going 'condo'.   ;)

[firefighter ontheside]

I love it.  I've thought of doing the same thing.

[thecfarm]

Tom is moving on up.

[Tom the Sawyer]

 8)

[Brad_bb]

I don't understand what use the pallet racking serves?  Especially when you could just stack 3 lifts on top of eachother and have the weight benefit as Yellowhammer indicated.  I'm just finally putting pallets together for air drying.  Before this I've just stacked and stickered separating lifts using 3.5" square stickers and stacking 2 or 3 at a time.  The benefit of the lumber pallets is that you don't have to move big sticker if you ever need to move lifts.  Pallets make the lifts easy to lift and set down.

[scsmith42]

I don't understand what use the pallet racking serves?  Especially when you could just stack 3 lifts on top of eachother and have the weight benefit as Yellowhammer indicated.  I'm just finally putting pallets together for air drying.  Before this I've just stacked and stickered separating lifts using 3.5" square stickers and stacking 2 or 3 at a time.  The benefit of the lumber pallets is that you don't have to move big sticker if you ever need to move lifts.  Pallets make the lifts easy to lift and set down.

Brad, the primary benefit is in material handling.  If you stack lifts on top of one another and need to access the bottom lift, you have to remove the other two lifts and then restack them.  This takes time.
By using pallet racking, Tom only handles the material that he needs to access.  This is a significant time saver when processing lumber.  He can only handle the product that he needs.

[Tom the Sawyer]

Systems are based on the particular needs of our markets.  If your lumber is going to be used in great quantities then maximizing production would be a priority.  If your lumber is going to be hidden inside of a wall or an attic, or as the substrate for another material, then its consistency in size, and strength may be your priority.  Most of my lumber is used for woodworking, cabinets and furniture, so appearance is a priority.  Character lumber sells before commodity lumber, and at a premium.   ;)

Lumber stacked outside, without protection, changes color rapidly, more so on the south and west sides of stacks. Within the confines of my particular location, I'll need to stack lumber outdoors, and yet protect it from color changes, while waiting to go in the kiln.  The racks will have a roof structure (the steel was picked up this week, as was the lumber for the roofs) that overhangs the racks 1' on each side.  There will be shade cloth all of the way around the racks, hanging from inside the eave of the roof frames.  

We are prohibited from building permanent structures within 30' of property lines. This pallet rack system is considered a portable, temporary structure.  If I had loads of space, and a larger budget, or operated on a larger scale, I might have approached it differently.   smiley_sidelightbulb

[Brad_bb]

Ok, I get it now.  The racking will be used as a structure to act as a building to protect the DRY wood, and to allow customers to pick through each lift as you sell it.

I assume you're not selling until it is air dried down to 12-15%? For the air drying process, you can still stack on top of eachother until it's ready to sell.   

[GeneWengert-WoodDoc]

The cost of moving air drying lumber stacks is around $3 per 1000 bf. The extra weight when using conventional air drying stacks on top of each other can easily add to flatness and increased value over $3 per MBF.  So, if we have separate stacks with straps or other warp prevention, I would think that such straps or other technique could cost more than $3, but even so it is a small cost.

[Tom the Sawyer]

Brad,

It is not for storing dried lumber, which would be counter-productive after kiln drying.  It is for air drying fresh cut lumber until it is ready to go in the kiln.  The shade cloth should protect if from rain, snow, and sunlight; yet permit air flow to reduce the moisture content below 20-25% before it goes in the kiln.  No fans so I guess it technically isn't a pre-drier.

[Brad_bb]

In that case, I'd definitely want to stack lifts on top of eachother to reduce warpage and have a roof over head(even if it's just tin).  What you gain in structure from the pallet racking, you lose in not having weight on the stacks.  Some kind of Carport structure to act as a roof would work, stacking lifts on top of eachother inside.  Some weight on the top stack is good too.  In my sheds right now I just stack a layer or two of timbers on top.  More weight would be better.  Do you have a forklift or something with forks to lift stacks with?  Maybe that is the disconnect here?  If you have to hand move everything.... well you need a machine with forks.

[Tom the Sawyer]

Clarification:  Although I do not have unlimited space or unlimited resources, I do have a need and a plan for resolving that need; air drying species and sizes of lumber that I commonly mill, prior to going into my DH kiln.  I have gained a tremendous amount of information from the Forum; some of those things I have adopted, and there are other things that I would never do - they're just not me.   :P  

My intent was to document how I resolved my pre-drying needs, for those who might be interested; not to convince anyone that this was the ideal solution, or that any other method was incorrect.  I accept responsibility for how I handle my challenges; it is not my intent to push answers to unsolicited questions.   ;)

Although I have not had any significant issues with lumber distortion from my stacking, I do have a design for a weight system, if it becomes necessary.  And, although it was mentioned earlier in this thread, yes, I do have a forklift, along with a tractor w/FEL & forks, and a skid steer with forks.  That is why I felt comfortable buying pallet rack and custom-made pallets for this project.

Fished the pallet rack roof today, shade cloth has been shipped.


 

The roof is modular, built in 6' sections in case I need to extend, modify or move it to another location.
 

 

[E-Tex]

Tom, the sawmill yard looks great!  

[Tom the Sawyer]

Finished hanging the shade cloth.  30% on the North and East sides, 80% on the South and West sides.  Not a good day for photos but... it did happen.  Now I just have to fill up some pallets between the mobile jobs.  ;D


 

[Crusarius]

That looks great. I just wish I had some flat ground I could work with.

[moodnacreek]

I also don't think you could get enough weight on if you are air drying hardwood. What I do is cover the ends of the piles with most anything to keep out the water, sun and wind. To my way of thinking the sides should not be obstructed with anything [for green lumber]. The only thing I have seen shade cloth used for was pine logs being kept wet in hot weather. Putting timbers on drying piles is something I don't do any more as packs of 1x work better. I sure would love to have those racks you built for dry lumber.

[Andries]

Y'know, if Tom found that his lumber would benefit from some top down gravity application, he could keep one weighted lumber pallet for the very top.
Scrap iron, concrete slabs or coffin lids, whatever.
He'd be able to shuffle his lumber pallets in the rack, then place the heavy "topper" onto the pile.

Looks very good Tom, well done.
As YH says: "taking steps to save steps !"  

[YellowHammer]

I was looking at your picture in reply 22, you have a real nice place.  Every bit of infrastructure you add will be a great benefit in the long run.
Good job.
 

[scsmith42]

Looking great Tom!  Thanks for taking us along with you on your journey.

Scott

[firefighter ontheside]

 Got my pallet racks today.  I have enough for 4 sections wth 2 levels each.  I paid $23 total for these at an auction.  Had to dismantle myself, but I think it was a great deal.  These should be heavy duty enough I think.  Not sure about the color, but I take what I can get.  Now I have to figure out where to set them up.


 

[Tom the Sawyer]

That is a wonderful deal.  My set was about $800 as I recall.  If outside, make sure you bolt them down.  That tall and narrow, with the shade cloth on, they can move in high winds (until you get them loaded down). 

[doc henderson]

I had a car trailer full of it and did not use it, so gave it back to my cousin.  Very well done Tom.  I may have to rethink.  Or if he still has not used it, it would be free to someone.

[tmbrcruiser]

Tom, how did you anchor the shade cloth? I build a drying shed and left both sides open then covered with shade cloth. One side I don't access lumber from so fixing the cloth with narrow boards works. The other side I used cable and rollers along the headers. Problem is the wind, blows the cloth like crazy.

[tmbrcruiser]

Should have added looks GREAT!

[Don P]

That looks good! I've got several set up in the shop at the sawmill loaded with stickered wood. I loaded a couple more shelves a week or so ago with 4/4 red oak to dry. Years ago Lowes was moving and had an auction. I went with the intention of buying a few shelves. Well they were selling it by the row, so I bid on a row and got it for what I thought was a good price. Apparently I then went into my happy place and was nodding to myself cause the next thing I heard, yup, I had won the next row too :D. Mamma was not happy!

[Tom the Sawyer]

The shade cloth comes with grommets every 2 feet.  Inside the roof framing I used large screw hooks to hang the shade cloth.  At this point, the bottom corners are restrained by bungee cords through 8x8x16 cement blocks.  Since the back would not be accessed, that shade cloth section is 36' long (32' run + 4' to cover the end).  If I need to access sections frequently, I may rig up a roll-up system for the front, 3, sections.

[Stephen1]

I am bringing up this agin as I am looking to purchase shade cloth for drying sheds. I not only need it for the summer to keep the sun off but more so now to keep the snow off. 
Where and what kind of shade cloth is everyone using?

[firefighter ontheside]

Ive bought several off of Amazon that I use to shade my deck.  They hang from the roof and hang down to the deck rail.  There are quite a few sizes available.  I just saw one 8x16 for around $45.

[Tom the Sawyer]

I got mine from a greenhouse supply company, available in custom sizes with grommets every two feet.  My pallet rack is oriented facing east and west.  On the east and north sides I used 30% fabric to increase air flow.  There are trees to the east so there isn't much sunlight to contend with.  On the west and south sides where there is more sun exposure, I used 80% shade cloth.