Plastic and metal sheds have gained great popularity over recent years, they are easily assembled, extremely durable and low maintenance - offering good looks and a long life.
But, if any dampness is present, metal or single walled vinyl clad structures will suffer from condensation similar to any enclosed, unheated space.
This is because the interior of a shed is warmer than outside and the problem starts with moisture, whether this is from the foundations or seepage from outside, rising up and condensing against the colder roof and wall panels. Droplets of water are formed, these fall onto the floor and the condensation process begins once more.
As many of these sheds do not include a floor as standard, you must take great care in assembling them properly. Making sure that the roof and wall panels overlap accurately is vital, and you should also check that every screw or plug washer is in place. There should be zero ingresses of water from any fixing.
Also, ensure you do not store damp items in the shed as this will add moisture. Instead, let wet gardening and leisure items dry out fully before storing.
It's a fact that condensation inside a shed is a difficult thing to prevent. However, building the base correctly is essential with a damp proof membrane covering the entire base area.
Instructions on how to construct a base can be found in How To Build A Concrete Shed Base.
After building the base, make sure the concrete is completely cured before proceeding, this can take over a week, and, after the shed is built, seal the inside with silicone along the base rails.
Solving The Problem
If the base is in place or condensation is already present, here are two suggestions to cure the problem:
a) Take the shed off its base and, with bearers to encourage air circulation and after making sure water won't collect underneath, construct a timber floor. Then screw the shed to the floor and use sealant again along the rails.
b) To create cheap but effective insulation, use meths to clean and dry polystyrene tiles and then choose a dry day to stick them to the inside of the roof.
Metal and plastic sheds have many advantages over traditional materials and, with proper preparation and careful construction, there is no reason why condensation should become a problem that prevents you from buying such fantastic products.