How do I stop mossy mould from coming through a compacted carport floor?

[rozzied1]

We had our backyard landscaped and tiered a few years back. 3 steps in the centre approx rise is 900mm. Both left and right of the stairs is treated pine H4's across to the carport which is 8.5m long x 3m wide. There is a constant growth of moss on the compacted road base floor of the carport. Any suggestions on how to fix this please?

[StevieB]

Welcome to the Bunnings Workshop community @rozzied1. We'd love to help.

Let me tag @Noelle and @Adam_W for their thoughts.

Stevie

[Noelle]

Hi @rozzied1 

The moss is growing in the cool shady environment that exists in your carport area.

There are moss removers available that you could use.  These range from bleach-type products to iron compounds. Do some research for a product that would suit your situation. My recommendation would be to use one that is suggested for pavers and driveways rather than a harsh bleach.

What would be more concerning to me is that the soil under the compacted road base may be quite damp and moisture is rising to the surface, thus encouraging the mossy growth. A permanent solution may be to look at your drainage and where rainwater from the carport roof is being directed. Fix the drainage and the moss problem will likely disappear.

[MitchellMc · Accepted solution]

That's some excellent advice that @Noelle has provided @rozzied1. I'd encourage you to seek the cause of the moisture and potentially install some drainage at the bottom of the retaining wall if needed. In the meantime, you can use 30 Seconds 5L Spray And Walk Away Concentrate to kill the moss.

You might find this is an ongoing issue that you'll need to manage, as retaining walls can often be quite damp due to sub-surface moisture transferring through them. Combine that with the constant shade from the carport, and it's a recipe for moss growth.

Please let us know if you have any questions.

Mitchell

[rozzied1]

We have been aerating the lawn leading up to the carport floor and are considering putting a rubble drain in before the edge of the carport and along the front of the raised wall. I do believe that drainage is to be fixed first. Thanks everyone for your help. Will let you know how it turns out.