Featured image for “6 steps to combat mould in your summerhouse…”
By Cara Mackay on 08 Apr 2016

6 steps to combat mould in your summerhouse…

Over the past few years, Scotland has experienced unprecedented levels of rainfall☔. Which is almost impossible to believe, as we were already getting a lot.

And that’s caused a lot of people around Scotland to face some issues around mouldy summerhouses. Not ideal, especially after spending a tonne of money on creating your dream garden. 

At Gillies & Mackay, we no longer build summerhouses, and our specification has completely changed in order to combat this additional rainfall and ensure that you have a fully watertight structure. Plus, the customer care guidelines we give out have changed as well. 

But after 30+ years of handcrafting timber Summerhouses, you start to really understand why these buildings behave the way they do when they’re not looked after properly.

So, in this blog, we’ll explore why you’re getting mould in your summerhouse. Plus, we’ll share six easy steps on how to get rid of it.

If you don’t fancy reading the whole blog then you can watch this video our Cara recorded on how to combat a mouldy summerhouse.

Why do you get mould in your summerhouse?

Set the scene; you’ve not been in your summerhouse for a while, then one day the sun comes out and off you pop with a cup of tea and that really good book you’ve nearly finished.

However, when you arrive at your summerhouse the doors are stuck and there is this black mould that has appeared?! YUK!

What on earth?

How could this be?!

That rain that we were talking about has a lot to answer for. And if water ingress gets into your summerhouse, or moisture builds up then you could find yourself with a case of a mouldy shed.

Bit of a pain, right? So ideally it’s something we’d like to avoid. 

How do you prevent your summerhouse from getting mouldy?

Prevention is better than cure as they say. And the same goes for mould in your shed or summerhouse. 

There are many ways in which you can prevent moisture from building up in a single-skinned building (single-skinned, ie no insulation or lining).

Ultimately, it’s caused by moisture so it’s your aim to STOP🛑 moisture from building up in your summerhouse or shed.

Firstly ensure your building is properly aired – moisture collects in the timber through ingress and needs a way to escape!! When a building is not aired it invites moisture to build up and this creates mould spores.

Pin those doors back and get the air flowing. Circulation stops the warm heat from staying stagnant inside and creates a through-draft which dries the timbers. You’ll need to do this especially if you aren’t using it for a while due to weather or whatever reason.

This is particularly evident in buildings where people may store damp (it doesn’t have to be wringing wet to be damp) furniture, gardening equipment, bikes or golf clubs. So make sure anything you store in your timber building is DRY. 

If you get mould/blackening it is unfortunately now irreversible. However, it can be stopped from spreading any further and reduce the impact that the current mould has on your building. 

How to treat a mouldy shed or summerhouse…

Right! The mould is already there, you can’t change the past. But you can stop it from spreading further and this is what we recommend.

  1. Remove all furniture and fixings from the building.
  2. Apply neat bleach (straight out the bottle, wearing gloves and old clothes with all doors and windows open) with a sponge to all affected areas. This will lighten the blackening considerably (not completely).
  3. Leave the building to air for a day.
  4. Apply an anti-fungal/pesticide to all the timbers inside the summerhouse; we find PermaGuard works well.
  5. Leave the building to air for a day.
  6. After that, you may wish to apply some colour to the inside to cover up the staining caused by the blackening.

I would suggest using Sadolin Quick Dry watered down to give a classic nautical look as I have done to my show studio.

I used Gregorian Grey Sadolin Quick Dry and I watered it down by one-third, to give it a light consistency.

Vd lining - scandinavian redwood

Please be aware all online colour charts are not a great representation of the actual colour when on wood

Get advice on your new summerhouse…

At the end of the day, if you’re reading this blog you’ve probably already got mould in your summerhouse or timber building. It’s not the end of the world, the structure itself is fine, it just needs some care and attention and these 6 steps will help you achieve that.

But, if you’re still in the stages of deciding whether or not to get a summerhouse, and are just really meticulous about buying a building that keeps the water out, we can help.

Our U12m2 Garden Rooms are all-season garden buildings that are completely watertight. Book a consultation with our team to find out more!

book a consultation

Join the Shedlife Clan!

* indicates required