Kiln dried scaffold boards gone mouldy?

[Evelina69]

We got some kiln dried new scaffold boards for a project and they have been stored inside for a few weeks. Where I had them had no ventilation atall and they have now gone mouldy and regained a huge amount of water.
I presume the issue lies with no air circulation?

 

[Daniel2]

Yes, and how do you know they have gained a lot of water ?

 

[Evelina69]

Yes, and how do you know they have gained a lot of water ?

Meter was reading maximum moisture

 

[Daniel2]

A primary condition for storing/drying timber is that the individual boards
are well ventilated.

 

[baldkev]

I think what daniel is getting at with the above post, is that ideally the boards would be stickered ( stacked with spacer timbers inbetween to allow airflow around all faces of the boards )

Couple of things..... firstly, have you sorted out the storage issues? I.e dry with air circulation? If they took on a lot of moisture, presumably they are in an outside shed or single skin garage etc?

I would prioritise getting the stickered and dry them out ( heat, dehumidifier etc ) and then go buy yourself some oxalic acid.

Once dry and lets hope they dont cup/ twist / bow , mix a tablespoon of oxalic with a mug of hot water, liberally paint on and hopefully it'll return to fresh looking timber after 10 minutes. May need a couple of goes. Then rinse with clean water and dry it all out again ( stickered , dehumidifier )

Or send them to me, my tower scaffold needs a revamp

 

[Daniel2]

@baldkev ,
You explain it so much better than me.

 

[Fitzroy]

A kiln dried board should have a moisture level of c.15%. Unless they have been stored in a room with high humidity, like a damp cellar I’m amazed that in a few weeks they have gone mouldy. What room have they been stored in?

A 1” thick board will take a year to dry in a well ventilated area, conversely a dry 1” board will take a good few months to take on any level of moisture increase. The surface could get damp if the room is but the bulk of the board should be unchanged.

 

[baldkev]

I would imagine its been sat directly on a damp floor and a few weeks could easily be months ( time passes so quickly )
Another question might be how reliable the meter reading is, but the mould still needs stopping.

 

[Daniel2]

I guess the meter is only really reading the surface, timber may well
be drier further in.

 

[Sgian Dubh]

A kiln dried board should have a moisture level of c.15%.

Not necessarily so. Kilning for construction grade wood, including scaffolding boards if they're actually kilned, is targeted at ±20% MC to get the material below the so called dry rot safe limit.

Kilned furniture grade wood in Europe has a target MC of ~11 -12% MC. In North America, the target for kilned furniture grade wood is 7%MC ±2%.

True, after kilning, or any other form of seasoning, wood adjusts its moisture content percentage either up or down in response to the RH circumstances in which it finds itself. Slainte.

 

[Fitzroy]

I was just a bit suspicious about the kiln dried scaffold boards. There are lots of online places that seem to reclaim them and sell as kiln dried ready to make rustic furniture. They claim low moisture levels. If the OP had purchased such I wondered where they could have been stored to gain sufficient moisture to mould in such a short period.

 

[MARK.B.]

I have piece or two of Kiln dried Wood sat in racking and to my shame stacked badly on the floor , Sadly it's a bit like an MOT as its only valid for a very short time. Those Kiln dried boards could have been stacked away for quite a while before you get them , probably in conditions less than ideal . Did you happen to test them on delivery ?.