On Mon, 04 Jul 2011 15:59:24 +0100, Martin Brown
wrote:

On 04/07/2011 15:49, john brook wrote:
We have a sheet steel garden shed, and with any sun at all it gets
unbearably hot inside.

We put up polystryene slabs under the roof, but that was to stop the
condensation dripping down inside in the winter. It does not help with the
problem of the shed getting too hot.

There is a limit to what you can do in a small space without any
airflow. Paradoxically your best bet might be to glue aluminium foil
onto the underside of the polystyrene slab. This slows down ingress of
solar heat by making it harder for the polystyrene to radiate energy.

Grateful for any suggestions as to best how to keep it cooler in this warm
weather, please.

The other trick is to make the exterior partially or entirely self
shading by having a second outer skin on battens. Ivy works pretty well
as it includes its own airconditioning and looks better than sheet steel.

Trying to cut out holes in that tin sheeting would I guess be a difficult
task, and I've no idea if it would be of much help? Thanks for any advice.

Letting the hottest air out the top and allowing cooler air in at ground
level will help a bit. You want a vent that lets hot air out but doesn't
allow rain to get in.

Regards,
Martin Brown
Ridge vents and screened opening in the base.