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View Full Version : another thread about weathering of HW decking prior to coating















treefan
17th December 2019, 12:16 AM
Hi ,

I have small deck to lay, 80% underroof

I am not concerned about any leaching from decking staining downstream materials (as this is already happening from green Hardwood subfloor)

I have some air dried White Mahogany decking 85mm wide

I was thinking about coating both sides and ends of decking boards with aquadeck prior to laying on deck to provide some protection from decay and stop differential drying between top and bottom of boards

If I want to coat underside I would like to do this before laying- therefore cant let weather after i lay it

Also I am impatient to get the thing built !


Options -
1) coat and lay
2) Napisan , coat , lay
3) Lay , weather , napisan , coat

I know there are many discussions about this , but wanted to add the intent of coating underside of decking into the mix ,
cheers
Ben

Skew ChiDAMN!!
17th December 2019, 11:16 AM
I'm not familiar with the properties of White Mahogany so can't be specific.

Still, the 'best' timbers for decking are slightly oily, hence the trend to let them weather or washing down with Napisan before sealing. This is primarily to remove the surface oils, allowing the sealing coat time to penetrate somewhat while curing.

Washing down with Napisan also removes any dirt, oils, etc. walked onto the deck by the installer or bystanders during the laying process. It's definitely my preference, as weathering allows too much time for other problems to occur... such as bird droppings, spillage of food/drink, etc. which are much harder to get out. :rolleyes:

I like the idea of sealing both sides; it is, in general, good practice. But time consuming, which is why it's almost never done for decking. ;)

For a small deck, I reckon 'why not?'

The only thing I'd be careful of is cutting to length. Were I to do this, I'd seal all of the boards as suggested but wouldn't cut any until actually laying and fixing them. It'd be a simple matter to seal the cut ends and work elsewhere while letting 'em dry.

This would give you better accuracy than trying to measure and cut loose boards...