"paddyenglishman" wrote in message
ps.com...
On 16 Aug, 11:22, Eddy Bentley
wrote:
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.
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