
Your summerhouse is looking gorgeous there in your garden, and you’re delighted with it. The next job is to decorate to make it beautiful inside and out.
But hang on… How do you paint the inside of a summerhouse?
What sort of paint do you use?
A single-skinned building has one layer of timber between the inside and the elements. This description applies to most sheds and summerhouses. They consist of a frame and one single layer of timber that’s fixed to the frame in panels.
What does this have to do with paint? Well, this is crucial information when it comes to knowing how to paint your summerhouse or shed, inside and out.
Why is it important to paint my summerhouse?
First of all, you should always paint the outside of a single-skinned timber building. Paint protects the building from the elements – it helps keep water out and it stops the sun’s UV rays from breaking down the timber walls. It’s like putting a coat on your shed or summerhouse to keep it dry and protected from sunburn.
But what about the inside of your summerhouse?
What’s the story there?
Once again, the answer to this question depends on whether or not your summerhouse is single-skinned.
Paint doesn’t just come in many colours. There are tons of different types of paint.
Should I use oil- or water-based paint for my summerhouse?
Once upon a time no professional painter would ever have suggested water-based paint. That’s because once upon a time, water-based paints were pretty rubbish. Oil-based paint was used instead.
But eventually, the government decided that it probably wasn’t a brilliant idea to have everyone breathing in dangerous chemical fumes from oil-based paint, and by this point, water-based paints had improved dramatically. Therefore your best paint option for a summerhouse exterior is water-based, microporous paint.
Timber is a natural material, and like all living things, it needs to breathe. Water and air should be able to get into and out of timber to keep it healthy. With breathable paint, tiny micropores in the surface of the paint allow this to happen. Moisture and air can move into the timber, but crucially, it can get out again. This stops your summerhouse from leaking or rotting.
If your building is single-skinned, then water-based microporous paint is what you need for both the exterior and interior of your summerhouse.
We recommend Sadolin, but if you choose a different brand, water-based and microporous are the two main qualities you want to have.
Do I have to paint the inside of my summerhouse?

Absolutely not! If you’re happy with the natural timber finish inside your summerhouse, then leave it be. The exterior coat of paint will protect the summerhouse just fine.
But if you do want to spruce up the interior, what are your options?
Can I varnish the inside of my summerhouse?
Please don’t.
If your summerhouse is single-skinned and in a Scottish garden, the timbers will always contain some amount of moisture. If you varnish timber that has moisture in it, the moisture will be trapped inside the varnished wood, and over time the wood will turn black. Not only is this unattractive, but it’s also bad for the timber.
Varnishing is like wrapping your timber in cling film instead of giving it a breathable raincoat. Remember – timber is from trees and trees need to breathe!
Can I paint the inside of my summerhouse?
Don’t worry – you can still have the decor of your dreams. But if the building is single-skinned, make sure to use the same sort of paint that you’d use on the outside of your summerhouse. Sadolin or whichever water-based, breathable paint you’ve chosen will be great.
Sadolin comes in so many colours that we’ve had to choose a selection to avoid needing a massive building to keep our paint in. But your paint supplier can provide you with any colour you fancy.
Can I use emulsion paint inside my summerhouse?
There is one situation where all my previous advice can be ignored. If your summerhouse is lined and insulated then it is no longer a single-skinned building.
If your summerhouse is lined with timber, you can paint it with any sort of paint you like, because this layer isn’t being exposed to moisture. Emulsion, gloss, varnish, dodgy watercolours from that random paint set you found in the loft – go for your life!

Here you can see the painted lining and unpainted ceiling of The Vorlich summerhouse.
Is my summerhouse single-skinned?
As long as you can answer this very important question, you can make a good decision about how to paint your summerhouse.
Remember that:
Single-skinned = water-based, microporous paint
Lined & insulated = any type of home decorating paint
If you’re a Gillies & Mackay customer, your building must be painted with Sadolin to validate your guarantee. We’ve found it to be the most reliable way to protect your shed, summerhouse, garage or garden room.
If you’d like to see a selection of Sadolin colours in person, come on down to our Show Area. You’ll see single-skinned and insulated summerhouses with painted and unpainted interiors. You might even get some decorating inspiration!