Hello!
I have a short-term project underway. I need to temporarily store freshly dried furniture wood for a maximum of a few months. I know, wrong season for this, but in this case, the choice is between throwing the wood away or doing something NOW.
I've considered various approaches here. Everything from wrapping with shrink wrap and storing outdoors to renting an insulated container. What I've somewhat settled on is building temporary storage with a heater that maintains about 18°C. The idea is that the wood will be able to maintain the right moisture level and even out (it comes out of the dryer with uneven moisture content).
The wood will be 3.5 m long, so I'm thinking of having the storage about 3.7-3.8 m long. Approximately 1.2 m wide and 2 m high (internal dimensions).
I will have some sheets of polystyrene (XPS) left over from the drying chamber. I thought I could glue them together to create a floor and, if I have enough sheets, a ceiling as well. This way, there is insulation from the ground and a barrier against heat loss upwards.
The question is how to handle the space between the floor and ceiling. My initial thought is that it's not worth insulating the walls. We're talking about a space of maybe 10 cubic meters that needs to be kept at most 18 degrees above the outdoor temperature (Skåne, rarely goes below 0°C).
Option 1: Just stack the wood and wrap with a tarpaulin on top of a polystyrene "pad" and then place another polystyrene pad on top, securing with straps. Heater inside the tarpaulin. Simplest. Probably cheapest. You would need a little frame around the heater to avoid fire risk, but nothing more than that. Ugly but functional?
Option 2: Have posts of some sort in the corners. They can rest on a polystyrene pad and hold up another such pad. You could wrap a tarp around it, and thus have something approaching a small shed, a bit neater than just a pile of boards. You can have one short side openable, making it easier to have an overview of what's inside, find a board of a certain size, etc.
Option 3: Framed construction. Polystyrene pad and ceiling. Framed walls, C-C 600-600 or 1200-1200 mm. One short side can be a "door" (door = a 1200x2500 mm OSB board with hinges on one side). A big advantage of this approach is that I have support for some "shelves," i.e., beams that go across from long side to long side. Then I could sort the wood on the shelves.
Could go different ways with this:
a) Tarpaulin outside of framed walls? Or maybe sheet metal?
b) 10 mm OSB on the inside of the walls to get some insulation from air inside the walls?
c) Do I need ventilation? Some air holes somewhere? Or two?
d) Sheet metal on top of the roof to protect the polystyrene sheets?
Right now, I'm leaning towards choosing between options 1 and 2. Option 3 feels a bit like a waste of work and materials. One must keep in mind that this should stand for about six months and then go to the dump, plain and simple.
Ideas? Opinions? Other options? How would you do it? Do you agree that a 2000 W heater with a thermostat should be able to keep the storage reasonably stable at 18 degrees? How do you think it will be with moisture? We have 90+ percent humidity in Skåne. How much condensation do you think there will be on the walls if they are just a tarpaulin? Will it be a problem, or will the heat loss there be significant enough that there won't be much condensation?
I have a short-term project underway. I need to temporarily store freshly dried furniture wood for a maximum of a few months. I know, wrong season for this, but in this case, the choice is between throwing the wood away or doing something NOW.
I've considered various approaches here. Everything from wrapping with shrink wrap and storing outdoors to renting an insulated container. What I've somewhat settled on is building temporary storage with a heater that maintains about 18°C. The idea is that the wood will be able to maintain the right moisture level and even out (it comes out of the dryer with uneven moisture content).
The wood will be 3.5 m long, so I'm thinking of having the storage about 3.7-3.8 m long. Approximately 1.2 m wide and 2 m high (internal dimensions).
I will have some sheets of polystyrene (XPS) left over from the drying chamber. I thought I could glue them together to create a floor and, if I have enough sheets, a ceiling as well. This way, there is insulation from the ground and a barrier against heat loss upwards.
The question is how to handle the space between the floor and ceiling. My initial thought is that it's not worth insulating the walls. We're talking about a space of maybe 10 cubic meters that needs to be kept at most 18 degrees above the outdoor temperature (Skåne, rarely goes below 0°C).
Option 1: Just stack the wood and wrap with a tarpaulin on top of a polystyrene "pad" and then place another polystyrene pad on top, securing with straps. Heater inside the tarpaulin. Simplest. Probably cheapest. You would need a little frame around the heater to avoid fire risk, but nothing more than that. Ugly but functional?
Option 2: Have posts of some sort in the corners. They can rest on a polystyrene pad and hold up another such pad. You could wrap a tarp around it, and thus have something approaching a small shed, a bit neater than just a pile of boards. You can have one short side openable, making it easier to have an overview of what's inside, find a board of a certain size, etc.
Option 3: Framed construction. Polystyrene pad and ceiling. Framed walls, C-C 600-600 or 1200-1200 mm. One short side can be a "door" (door = a 1200x2500 mm OSB board with hinges on one side). A big advantage of this approach is that I have support for some "shelves," i.e., beams that go across from long side to long side. Then I could sort the wood on the shelves.
Could go different ways with this:
a) Tarpaulin outside of framed walls? Or maybe sheet metal?
b) 10 mm OSB on the inside of the walls to get some insulation from air inside the walls?
c) Do I need ventilation? Some air holes somewhere? Or two?
d) Sheet metal on top of the roof to protect the polystyrene sheets?
Right now, I'm leaning towards choosing between options 1 and 2. Option 3 feels a bit like a waste of work and materials. One must keep in mind that this should stand for about six months and then go to the dump, plain and simple.
Ideas? Opinions? Other options? How would you do it? Do you agree that a 2000 W heater with a thermostat should be able to keep the storage reasonably stable at 18 degrees? How do you think it will be with moisture? We have 90+ percent humidity in Skåne. How much condensation do you think there will be on the walls if they are just a tarpaulin? Will it be a problem, or will the heat loss there be significant enough that there won't be much condensation?
None of these solutions are viable over the winter in Skåne (and probably nowhere else either).
Solution 1 is a no-go due to the obvious fire risk.
Solution 3 is approaching a real shed/storage with proper materials and constructions, and that's what's needed. Everything else will tear apart and/or get blown away in the first autumn storm.
Of course, I agree that it feels like overkill to build a real storage for this project.
So, isn't there a garage/storage that can be used?
Instead of a heater, a dehumidifier should do the job better. The cheap ones only need 5-10C to work decently.
If no usable space is available, how about acquaintances or family? Anyone there who has space you can borrow for a while?
Solution 1 is a no-go due to the obvious fire risk.
Solution 3 is approaching a real shed/storage with proper materials and constructions, and that's what's needed. Everything else will tear apart and/or get blown away in the first autumn storm.
Of course, I agree that it feels like overkill to build a real storage for this project.
So, isn't there a garage/storage that can be used?
Instead of a heater, a dehumidifier should do the job better. The cheap ones only need 5-10C to work decently.
If no usable space is available, how about acquaintances or family? Anyone there who has space you can borrow for a while?
I can certainly rent/lease space. But then I would have to move timber there, about 1 ton, each time I empty the dryer. Each time I want to sell/show a plank, it would have to happen where they are located. It can definitely work, but I would prefer a solution where I have them where the sawmill and the dryer are.
I appreciate your advice to build robustly considering the weather. At the same time, I've lived here for seven years and haven't seen a winter yet. Of course, it can happen though, and it only takes once.
A dehumidifier seems too cumbersome. You set the desired relative humidity, but as the dehumidifier heats, heat losses are very large and the outdoor temperature varies a lot, the temperature will vary greatly. From perhaps 5-10 degrees during the night to 20-25 during the day (inside the storage). Even with the same relative humidity, the absolute humidity becomes very different.
Better with a heat fan. Absolute humidity outside doesn't vary much and if you heat to a set temperature, the environment becomes stable and thereby the wood's moisture content.
But...yeah. I have to think about something like variant 3 or a beefed-up variant 2. What do you think about condensation inside? Is ventilation needed?
I appreciate your advice to build robustly considering the weather. At the same time, I've lived here for seven years and haven't seen a winter yet. Of course, it can happen though, and it only takes once.
A dehumidifier seems too cumbersome. You set the desired relative humidity, but as the dehumidifier heats, heat losses are very large and the outdoor temperature varies a lot, the temperature will vary greatly. From perhaps 5-10 degrees during the night to 20-25 during the day (inside the storage). Even with the same relative humidity, the absolute humidity becomes very different.
Better with a heat fan. Absolute humidity outside doesn't vary much and if you heat to a set temperature, the environment becomes stable and thereby the wood's moisture content.
But...yeah. I have to think about something like variant 3 or a beefed-up variant 2. What do you think about condensation inside? Is ventilation needed?
Odd solution ... 
But a caravan?
There are sometimes those that are given away, which are of decent quality. The roof might leak on such ones.
But it can be temporarily sealed - remove all fabric, tear out the interior so you have space for your material. Build a frame or something.
And bring everything in through the window.
After the need is over - give it away again. It's usually the frame everyone wants to build their own trailer, so what you do with the interior doesn't matter.
But a caravan?
There are sometimes those that are given away, which are of decent quality. The roof might leak on such ones.
But it can be temporarily sealed - remove all fabric, tear out the interior so you have space for your material. Build a frame or something.
And bring everything in through the window.
After the need is over - give it away again. It's usually the frame everyone wants to build their own trailer, so what you do with the interior doesn't matter.
The kiln needs to be emptied and loaded with a new batch immediately after drying to have time to dry all the wood, unfortunately. It only takes about 1.5-2 cubic meters at a time. It will just be a box made of XPS panels and a Logosol WDU unit.V vectrex said:
Interesting solution. I'll check what's available...L larka742 said:Odd solution ...
But caravan?
There are occasionally ones given away, which are of decent quality. The roof might leak on such ones.
But can be temporarily sealed - remove all fabric, tear out the interior so you have space for your material. Build a frame or something.
And bring everything in through the window.
After the need is over - give it away again. It's usually the frame that everyone wants to build their own trailer, so what you do with the interior doesn't matter.
I don't agree with you that heat is better than a dehumidifier. The moisture content of the wood is controlled 99% by the surrounding air's relative humidity, not the absolute humidity.
Admittedly, you can control the relative humidity by regulating the heat, but it is significantly easier to do so with a dehumidifier. The absolute humidity of the outdoor air can vary quite a bit in the winter. If you then run a heat fan on a thermostat, the relative humidity will also vary quite a bit in your temporary storage.
Admittedly, you can control the relative humidity by regulating the heat, but it is significantly easier to do so with a dehumidifier. The absolute humidity of the outdoor air can vary quite a bit in the winter. If you then run a heat fan on a thermostat, the relative humidity will also vary quite a bit in your temporary storage.
Do not believe in this with tent/tarpaulin if it is to become some form of economy in it. Insulating around is likely quickly recouped even if it's just for one season.
It becomes a bit theoretical, really, since EMC 7% is probably around 35-37% at temperatures 0-30 C.V vectrex said:
My reasoning was that the temperature outside varies more than absolute humidity, and thus a thermostat should be able to keep the environment more stable than a hygrometer. The absolute best would be to have both.
There is indeed one more advantage of the dehumidifier. You can have it warmer in the storage but maintain the same humidity. This way, the timber will dry more evenly faster.
The choice will likely be determined by what is available for sale on Blocket/FB marketplace at that time...
S
sinuslinus
Träskalle
· Östergötlands län
· 6 013 posts
sinuslinus
Träskalle
- Östergötlands län
- 6,013 posts
Buy an insulated container which you then sell after a few months. Then you can build a cart that you roll the lumber on in and out.
Spontaneously, I had the same thought as @sinuslinus - insulated container.K KristoSig said:
But otherwise in the simplest way. Rock wool/polystyrene/whatever. Even a simple insulation makes a dramatic difference compared to just a tarp. But I haven't thought as far as any potential condensation issues.