Cleaning Sandstone Walls

[Peza82]

Hi,

There wasn't a masonry section so decided to put it on general.

I bought this property back in December and it's taken me until now to get all of the inside work finished. Now my aim it to tidy up the front of the house, garden and stonework etc. The property is a sandstone bungalow and hasn't has any attention for a good few years. Also along the path and driveway the same stone has been used and needs some attention.

My plan is to start work this weekend, taking out the existing pointing, bedding in the top row of sandstones (house) due to having new gutters and clean the stonework and walls before repointing again. My uncle will be doing all the pointing but I wanted to get everything ready in the meantime.

The stonework on the house is generally quite clean so I wanted help on how to go about giving it a little refresh as it is now 40 years old. What equipment and products/ cleaners to use?

My next job will be to then start on the walls which are in a lot worse state. One of the small walls will be taken down, the old crumbling stone disposed of. I then wanted to know what to use on this stone, has a lot of mound and black marks on it? When this is done I will then rebuild and add new cappings etc.

Any help would we very much appreciated. Had a look online and lots of conflicting info on whether to use chemicals etc.

Will try and add some photos if possible.

Thanks

 

[Peza82]

View media item 84326 View media item 84327

 

[foxhole]

Jet washer.

 

[jj4091]

As foxhole says a pressure washer will clean those up without any trouble especially if you have a dirt-blaster attachment for stubborn areas. You could do the paths at the same time.

 

[Norcon]

A jet washer alone will cause irreparable damage causing the stone or concrete surface to foul quicker.
Especially if a turbo jet nozzle is fitted.
Best option is pour on sodium hypochlorite and let the rain do the washing or a light power washing with a standard nozzle.

That black lichen you see on your copings will be history after a dousing with sh.

http://www.pavingexpert.com/maintain_03.htm

They're saying dilute 10-1 and don't use neat.
You could comply with that if you want.

I use it neat and undiluted (which was recommended by my supplier) on concrete and works a treat. Very little power washing needed and less damage now to the surface.
I have 800sq/m of brush finished yard and avenue concrete.

Have a look at this..
https://www.youtube.com/watch?v=PBj0FBOc8nc

Yeah it getting the job done (albeit slowly) but the damage is irreverisible.

 

[jj4091]

Any help would we very much appreciated. Had a look online and lots of conflicting info on whether to use chemicals etc.
Thanks

Looks like more conflicting info Perhaps you need to experiment on small areas

 

[Peza82]

Cheers!

Should have mentioned, I have given the wall a once over with the jet wash, picture I used was one saved on my phone from before. The paving slabs on top came up like new but the stone didn't show much improvement.
I think I will try the SH on the stone wall when I have take taken it to pieces.

Maybe best just giving the house a little scrub with with a brush and not mess about with jet wash. Could make a mess a few years down the tine by the sounds of it.

Where can I pick up the sodium hypochlorite? Does it come as a liquid or powder?

I may see what it does to roof tiles also as that needs a clean up but I definitely don't want to just wash the roof in case of leaks.

Thanks for the help

 

[Peza82]

Ha, just read through the link, SH is bleach, will give it a go!

 

[Burnerman]

Personally I'd avoid any harsh detergents......the path and coping flags will come out fine with the jet wash, but as for the stones I'd use a wire brush - or just leave them be.
Do test a small area first if you decide on any bleaching agent!
John

 

[Norcon]

Cheers!

Should have mentioned, I have given the wall a once over with the jet wash, picture I used was one saved on my phone from before. The paving slabs on top came up like new but the stone didn't show much improvement.
I think I will try the SH on the stone wall when I have take taken it to pieces.

Maybe best just giving the house a little scrub with with a brush and not mess about with jet wash. Could make a mess a few years down the tine by the sounds of it.

Where can I pick up the sodium hypochlorite? Does it come as a liquid or powder?

I may see what it does to roof tiles also as that needs a clean up but I definitely don't want to just wash the roof in case of leaks.

Thanks for the help

Sodium hypochlorite is a liquid. I purchased 10 gallon for about £40 at my local hardware supplier who supply it for surface cleaning.
But I reckon it saved me at least £30 quid in petrol.
So you could try a local one near you.

Its also a common cleaner used for cleaning milk transfer tubing after dairy milking operations. Farm supply shops sell the stuff by the lorry load.

 

[Norcon]

Ha, just read through the link, SH is bleach, will give it a go!

Good stuff. Let us know how you get on.

Incidentally we use a guy now and again to scabble smooth finish concrete walls to leave them prepared for rendering.
He uses a jet washer!

 

[NicKarla]

I have read posts on the internet suggesting the dangers of pressure washing stone houses. I have also read many posts where people do it to their houses with no issues at all.

what I did notice was that all of the webpages suggesting you shouldn’t pressure wash your house was from those offering the service of cleaning houses .

6 years on how did it go? Have you or anyone experienced any ill effects of pressure washing stone built walls/houses?