cleaning block paving

[mercmanuk]

advise needed
ive just moved house and the rear garden is block paved,at some time the blocks have been coated with a sealer/laquer.the problem is this wasnt done when the blocks were new but later and applied over the surface dirt.ive tried pressure washing the blocks but since the dirt is under the sealer it makes no differance.they look terrible and it drives me crazy.any ideas what to use to remove the sealer,i was thinking of sandblasting but will this be to severe!.any block pavers on the forum.

cheers all

 

[DieselE]

Did the pressure washing have no effect at all? I only say that because my next door neighbour uses sealant and every couple of years removes it by pressure washing. Maybe it depends on how high a pressure your machine will deliver.

 

[guydewdney]

what about brick acid?

Theres a good few 'paving / driveway' cleaners out there -

 

[Flash]

An Industrial pressure washer would take care of the job easy. Also, applying household bleach would work.

 

[Howard]

A friend of dads had a paving cleaning business years ago ....

He used to use quite a high pressure washer ( 2500 psi + ) and hydrofluoric acid .....

Dangerous stuff, but there was nothing it wouldn't clean , not a clue where you would buy it though ....

 

[Flash]

not a clue where you would buy it though ....

Shops...

 

[mapleleaf]

Hi Baz

Try Rothwells in Rochdale - they sell all kinds of industrial cleaning products. I bought 2 x 5 litre containers of bleach the other week. for about £3 each

 

[Howard]

Shops...

No sh!t Sherlock ....

 

[mercmanuk]

my cleaner is 135 bar i think,lifted the surface grime but not the sealer,might call a few companys and do some brain picking

 

[fredfloggle]

A friend of dads had a paving cleaning business years ago ....

He used to use quite a high pressure washer ( 2500 psi + ) and hydrofluoric acid .....

Dangerous stuff, but there was nothing it wouldn't clean , not a clue where you would buy it though ....

I think you would be lucky to by hydrofluoric acid in bulk at any concentration - bearing in mind it's propensity to etch glass in a 5% solution , and being able to dissolve flesh -
Might be better to try a commercial brick cleaner like "DISCLEAN" , which while it may rot your socks will not make your house collapse in a smoking heap - I think Disclean is Hydrochloric acid based .

 

[Bobby Dazzler]

Is the affected area too big to replace? If the levels are still right, you could lift and replace.

 

[Satch]

Might want post your question up here:

http://www.pavingexpert.com/cgi-bin/ib3/ikonboard.cgi

Lot of useful info on the main site, e.g:

http://www.pavingexpert.com/sealants.htm