How to Clean a Dirty Shed

How to clean a dirty shed
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Like anything exposed to the elements, Backyard sheds can look shabby over time. Biological growth such as mold, mildew, and algae can give your shed an unsightly appearance which you will want to remove.

Tree sap and bird mess can also create stubborn stains on a shed roof that you need to clean off.

Regular cleaning should prevent severe stains from becoming a permanent blight on your shed. Fortunately, it is easy to clean a dirty shed and get it looking bright again.

How to Clean a Plastic Shed

Plastic sheds are very easy to clean. If you wipe them over with a wet cloth whenever you notice them looking dirty - like from bird mess - you'll help keep them looking tip-top throughout the year.

A regular hose-down whenever you are watering the garden helps keep down any severe build-up of grime too, but there are times when you want to get the shed gleaming.

A simple solution of warm soapy water - dish soap is fine - plus some white vinegar should, with a mop or sponge plus sufficient elbow grease, clear away all but the most stubborn stains.

You can powerwash if you prefer. Just use a lower power setting than cleaning pathways, keep away from vents so you don't flood the shed interior, and wash the windows by hand.

How to Clean a Metal Shed

Metal sheds should be cared for throughout the year to protect their appearance and longevity as well. They are relatively robust, but they can dent and rust and are still susceptible to staining from biological matter, bird mess, and general dirt and grime like other sheds. They'll keep smart-looking if you look after them throughout the year.

Routine maintenance is easy. Whenever you water plants in your yard, give the shed a quick hosing down. If you see any prominent stains, use a bristle brush and elbow grease with some warm soapy water to work the stain away, then hose off clean. Always read the recommendations of the shed manufacturer first, though.

A pressure washer is probably the easiest way to clean stubborn stains off a metal building. You shouldn't need to do this more than a couple of times a year if you also give the shed a quick hosing down during spring and summer.

If your shed is located under trees (inadvisable) and collects tree sap deposits, you might have to power wash more often.

Use a low water-pressure setting and stand back from the shed surface when spraying the surface to avoid damaging painted surfaces and coatings. Avoid spraying water into ventilators and wetting the shed interior.

To manually wash a metal shed at any other time, hose down to wet the grime, then use a bucket of warm soapy water plus a non-abrasive brush or sponge and good old-fashioned elbow grease to get the job done.

How to Clean A Wooden Shed

Wooden sheds tend to take more punishment than sheds made from other materials and require more regular maintenance. Cleaning can sometimes take longer.

In addition to combating weather extremes throughout the year, wooden sheds also need protection against wood rot, wood-eating insects, and biological growth that can cause shed timbers to decay.

Cleaning the exterior of a dirty wooden shed can be relatively straightforward if it is painted or has plastic siding.

If your shed has a paint finish, then a wash with a bucket of warm soapy water may be all you need to do to clean it. If any paint gets removed while rubbing off any stubborn stains, retouch the paintwork when the woodwork is thoroughly dry.

If the shed has plastic siding, follow the cleaning routine for plastic sheds.

If your shed has a natural wood finish, cleaning can take more effort, and how much more will depend on the severity of the dirt. A mold and mildew cleaner applied to the woodwork can clean away mild staining, but you may need to use a second coat if the staining is heavier.

Wood with a surface build-up of biological matter or bird poop will take longer to clean. The physical presence on the surface of the wood will need to be scraped or brushed off. Then you should apply the fungicidal wash to obliterate it. You may need to use several more mold and mildew remover coats to solve the problem.

Once you have cleaned the shed and the wood has thoroughly dried, you should apply a coat of clear wood preservative.


Keeping your shed clean ensures that it looks good in your yard and lasts longer than if left to decay. Check your shed periodically throughout the year, deal with any issues when you notice them, and your shed will serve you well.

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  2. How to Spring Clean, De-clutter and Makeover your Shed

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