Effect of pressure-washer on preserved wood?

 

Does anyone who uses a pressure-washer around the house or garden know
if it has a bad effect upon wood which has been treated with wood
preservative?   I have a lot of horizontal and vertical wood around this
new house and garden here and I am inclined to apply a few coats of wood
preservative - as soon as the weather allows.  However, after the autumn
rains and leaf-fall I expect there will be a build-up of
dirt/grime/slime, in corners particularly, and so I am wondering if
using a pressure-washer will remove a noticeable degree of the
preservative in such places . . . in which case it would be sensible not
to go buying us a pressure-washer!

Thanks.

Eddy.

 

On 16 Aug, 11:22, Eddy Bentley

it depends on the pressure of the washer , the higher the pressure the
more damage . if it is a low pressure domestic  one damage will be
minimal . i learnt the hard way stripping pine and destroyed some old
cupboards with a industrial pressure washer.best advice i can give is
stand well back and try a section thats not that visible to everyone
first.as for preservative damage  who knows.

 



This is an opinion based on using a pressure washer for domestic use, and
occasional s=use on ld wooden boats. It is backed up by seeing larger
pressure washers in industrial and marine situations:

1) The sort of pressure created by a domestic pressure washer wont do much
harm to hardwoods, but might damage the softer fibres of the likes of pine
and spruce.
The moral is to be careful and do a few experiments first.

2) With preserved timber, it will probably wash the preservative salts out
of the surface layers.
Moral is to be careful, wear protective clothes and a suitable mask, the
salts are preservative because they are poisonous!
Second moral is to let the timber dry out and re coat it.

Having said that, removal of the dirt/grime/slime i probably better than
leaving it!

Thats my two pennyworth!
Cheers

John

 

On Thu, 16 Aug 2007 10:22:45 GMT, Eddy Bentley


We have a teak garden bench which in the past got regularly 'oiled'
(as did those sitting on it, but a different sort of oil!). But the
surface had gone black and grubby over the years so I pressure- washed
it, using a small Karcher washer (can't remember the model and it's
down in the shed...). Came up a treat. Got rid of all the black crud,
and left a nice clean silvery aged-wood finish. It also brought up the
grain, which was a bonus, but I imagine this would be more pronounced
and possibly less desirable on a softer wood with a wider grain.



--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net