Tools getting rusty in shed

Murray13

Hi folks,

I've recently put a new corrugated iron and clear plastic roof on a small 4m x 5m shed. The shed is a single course of block. there is a double glazed window and pvc door. There is plenty of ventilation in the eaves / edges of the roof.

I've started putting tools in there that have been in dry storage for years. Now there is constant codensation on the roof and it drops on tools, work bench, shelves. The timber rafters are wet and getting mouldy. Hand tools are rusting badly and I've noticed codensation on power tools.

I want to get this sorted, clean up the rust and prevent this from happening again..

What are my options here, I don't think I have the space for internal insulation. I'm thinking, dehumidifier might be the solution or putting a fan and heater in there to keep the damp air moving out.

Note the concrete floor is bone dry.

Hope you can help.

magicbastarder

any chance to line the inside of the roof with WBP maybe?

10-10-20

Any shed or outbuilding which is subject to flows of air from outside will be subject to condensation on its contents when the external temperature drops on a cold night. Tools and metal objects with a high emissivity will loose heat first, and when they reach the dew-point of the cooling air, they will collect condensation on their surfaces and cause surface rust.

Ventilating will help but only if you're sufficiently insulated and not letting the shed get to the point where there is a high RH when the temp is dropping. Otherwise if you go down the dehumidifier route, the vents should be closed to a minimimum so that you're not trying to "boil the ocean".

magicbastarder

i don't have a lot of airflow in my shed and only occasionally have issues with condensation on tools; usually when there's a rapid increase in temp and humidity after a spell of cold, so the moisture in the warm humid air condenses on the still-cold tools.

it's got a felt on WBP flat roof, and is ventilated, but no 'cross' ventilation.

10-10-20

Many of my tools on wooden shelves are the same - they don't collect much condensation, but other tools such as saws on the far side of the shed which is cooler (due to shading from the sun) are very difficult to keep rust-free. I'd guess that much of this would also depend on the thermal mass (longer retention of heat) and quantity of metal items within the shed as there would be more surface-area for the same level of condensate within the air.

magicbastarder

probably not going to be massively useful, but something like this in the shed you'd occasionally wipe over tools, couldn't hurt.

https://www.youtube.com/watch?v=npKo1y2e8RI

The Continental Op

I get this all the time. My solution is to keep my tools in waterproof toolboxes and use tools that are less likely to get damaged by condensation.

This is my main toolbox I keep out in the barn for woodworking https://www.amazon.co.uk/gp/product/B001SY4TOU/ whenever I open it I give it a overhead spray of WD40.