What is this white Powder that has suddenly appeared on logs delivered a week ago?

[Rich05uk]

Hi all,

 

I had some new logs delivered from my usual supplier recently and have stored them in the same way as I always do in my usual log store and have never had a problem in the past but about a week later, many of them now have a white powder like coating on them that didn't exist when they were delivered.  The only thing I am aware of is that it was raining heavily on the day they were delivered so they got soaked, but again it's not the first time I've had logs delivered in the rain and I've never experienced this kind of problem in the past when they've got wet for a brief period so long as they were stacked in a well ventilated store afterwards.  Here's a picture of one of the logs.

 

Any Ideas?  Is it a problem as they seem to burn perfectly?

 

Cheers,

 

Richard.

 

Edited October 23, 2020 by Rich05uk
Correcting title

[Stubby]

10 minutes ago, Rich05uk said:

Hi all,

 

I had some new logs delivered from my usual supplier recently and have stored them in the same way as I always do in my usual log store and have never had a problem in the past but about a week later, many of them now have a white powder like coating on them that didn't exist when they were delivered.  The only thing I am aware of is that it was raining heavily on the day they were delivered so they got soaked, but again it's not the first time I've had logs delivered in the rain and I've never experienced this kind of problem in the past when they've got wet for a brief period so long as they were stacked in a well ventilated store afterwards.  Here's a picture of one of the logs.

 

Any Ideas?  Is it a problem as they seem to burn perfectly?

 

Cheers,

 

Richard.

 

Its not a problem , providing you have sufficient air flow through your log store and can keep the rain off . When you say " new logs " do you mean green , unseasoned  or just some more logs .  If they are green they won't be burnable till the following winter mold or no mold .

[Rich05uk]

1 hour ago, Stubby said:

Its not a problem , providing you have sufficient air flow through your log store and can keep the rain off . When you say " new logs " do you mean green , unseasoned  or just some more logs .  If they are green they won't be burnable till the following winter mold or no mold .

Hi,

 

Sorry I should have said, my supplier has advised that after harvesting trees they are extracted back to their processing site where they are stored outside in a log pile for at least 18 months before they are then processed and split where they are then stored in a barn with plenty of ventilation until they are ready for delivery to a customer.  Mine are a mixture of Hard and Soft wood logs and were split in March this year and only delivered to me last week, they had a MC of 25%-30% and there was no signs of this white stuff on them at the time.  They were then stacked there and then in my log store which has plenty of ventilation and is located in a sunny spot too.

 

The best way I can describe it is that it looks identical to efflorescence you sometimes see on brickwork.

 

I have been buying my logs from this supplier for almost 10 years now, a delivery of 3 m2 loose tipped every year to last through the winter.  I've never seen this white stuff on my logs before and have never had any problems burning them, I actually find them much better than kiln dried logs but that's a personal opinion and I certainly don't want to start a debate about naturally seasoned vs kiln dried. 

 

As I say, despite this white stuff being present on the logs, they burn as normal, giving out perfect heat with my stove sitting at 250c to 300c on a slow idle burn.

 

I was just curious as to what it was and if it is safe, I've read that certain types of mould can be at best an irritant and at worst carcinogenic.

 

 

[Steven P]

If it is in the stove when it is burning then no problem whatever it is. Not sure exactly what you are describing, you might want to limit how long logs with the mold are in the house. I wouldn't be too worried about it - my logs have a full range of things growing on them and they all burn just as well as each other.

 

Just reading you other comments, you might ask to get your logs delivered in March when they are freshly split and then store them yourself for the summer - might be cheaper 'unseasoned' and you will probably end up at this time of year with logs the same MC

[otter]

Some tree species like sycamore, pine and maple etc,  seem to attract mold anyway during the drying period. 

[fonzy]

1 hour ago, otter said:

Some tree species like sycamore, pine and maple etc,  seem to attract mold anyway during the drying period. 

Our Pine is particularly bad this year.  It is just on the sap wood at the log ends.  Doesn't effect the burning though.

[Vedhoggar]

Can’t view your image but it sounds like mildew (type of fungus), it will be because your logs got a soaking beforehand. Firewood delivered in spring or summer if get wet usually dry out if left a while before being stored but more difficult come autumn, if your logs are likely to be left out in the open try and schedule delivery on a day forecast to be dry or at least cover them up with a tarpaulin sheet. Mildew should dry up if logs stored in a dry well ventilated area and will brushed off (wear a mask), if logs <20% mc they will burn.

[Steven P]

3 hours ago, Vedhoggar said:

 if logs <20% mc they will burn.

If logs are > 20% MC they will also burn

[Rich05uk]

11 hours ago, Vedhoggar said:

Can’t view your image but it sounds like mildew (type of fungus), it will be because your logs got a soaking beforehand. Firewood delivered in spring or summer if get wet usually dry out if left a while before being stored but more difficult come autumn, if your logs are likely to be left out in the open try and schedule delivery on a day forecast to be dry or at least cover them up with a tarpaulin sheet. Mildew should dry up if logs stored in a dry well ventilated area and will brushed off (wear a mask), if logs <20% mc they will burn.

I've attached the photo as an attachment, hopefully you can see it now?

[neiln]

That is an impressive amount of powder isn't it!  I'm no expert but would also think fungus, which will stop as the wood dries, and won't affect the burn, but I wouldn't leave logs in the house for long and would try not to sprinkle that mess about.

 

Is it on many of the logs?