Steps, wall and patio going green

Hebrews12

Hi all

We had some building work done last year and in July, the work was completed and the builders had to put in a new retaining wall in our garden and we got them to put some new steps in and lay a patio. The problem is, we're only 5 months in and the brickwork, steps and patio have all gone green and have gone from looking lovely to looking awful. My questions are:

Is this because of the slabs/bricks they used?
Should they have put a double skinned wall or some kind of membrane on the retaining wall?
Is there anything we can do to get/keep them clean?

It's worth nothing that a lot of the area I'm talking about doesn't get any direct sunlight.

Thanks for reading.

C

glasgowdan

Do you get a lot of standing water on the patio? Or does it drain reasonably well?

Hebrews12

Thanks for your reply. It all drains pretty well.

EssexExile

Clean it with a pressure washer in the spring.

Furts

All retaining walls should receive a design and this includes consideration on how they are constructed and what materials are used. This design can be empirical and as an example nobody is saying consult an Engineer for retaining 300mm in a back garden.

If you are in a shaded area it becomes vital to consider the brick. A low absorbing brick is vital and for example LBC Flettons are useless in these locations. Conversely Class B Semi Engineering would be good. Render is just a disaster area. Intertwined into this is frost resistance - damp, algae covered bricks are prime candidates for spalling and failing in low temperatures.

The top of the wall should receive a water shedding, water resistant coping, with a dpc element underneath and an overhang shedding detail complete with drip grooves - or similar.

Behind the wall should be free draining material, and the design could include a geotextile, a land drain and weepholes. A coating should be on the back of the wall - though rarely, if ever, does this occur. Here think of RIW or similar products.

If all this sounds like news to you then the odds are the wall is not correct and possibly not correct in a multitude of ways. To be blunt it stands a high chance of having been bodged.

Countless bricklayers, and builders, are clueless on retaining walls - which is a great shame, yet a simple statement of reality. Over to you - what was specified, what was built, and what did you check up on?

Furts

EssexExile wrote: »

Clean it with a pressure washer in the spring.

If they are soft bricks, or LBC Flettons, then not recommended! But being pragmatic, a pressure washer should not be regular procedure on any wall.

Jonesya

Sounds like natural growth of algae and moss, if it doesn't get any sun then it's probably staying damp for long periods letting it grow.

Plenty of good advice here.
http://www.pavingexpert.com/maintain_02.htm

maninthestreet

If it's algae, just spray it with dilute bleach.

Davesnave

What's done is done. If the brickwork looks ugly, distract from this by growing trailing plants down and above it. Remember 'awful' is in the eye of the beholder and how the beholder adapts the situation to fit the microclimate.

Delay cleaning the patio slabs till April, or just do the walkway if there's a safety concern.

Plenty of plants grow in shade. Here are two links to help ypu see what's out there:
https://www.plantsforshade.co.uk/

https://www.rhs.org.uk/advice/profile?PID=100