Joined: Aug 2017 Posts: 725 Threads: 38
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Location: Herefordshire
Leave the doors and windows open (even if it's raining) for a few days.
Don't be tempted to use a dehumidifier. In a wooden building, all that they do is to draw more moisture from outside through the timber cladding, which will never dry out.
Does the floor have a damp-proof membrane? If it does, you don't really need to do anything more than letting it dry and then seal it, mainly to keep the dust at bay. If it doesn't, then it'll need a damp-proof surface of some sort.
Joined: Nov 2018 Posts: 215 Threads: 0
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Location: Norfolk
Car type: 1934 RP Saloon
Tony is right that a very small heater will make a huge difference when the shed / garage is insulated. A good way of introducing this heat is a domestic dehumidifier, which will also keep things dry (providing it is drained away outside). Lack of draught would then be an advantage to keep the heat and dry air in.
Joined: Aug 2017 Posts: 725 Threads: 38
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Location: Herefordshire
Bruce - Absolutely "No" to a dehumidifier in a timber building! I have seen so many problems caused by these of many years. A well-built timber garage will behave just a Ivor has described.
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Location: Buckingham UK
It is worth considering the science. Warm air holds more moisture than cool air but will have a lower relative humidity. Thus on an autumn day as the temperature drops the relative humidity rises until as the dew point temperature is reached condensation is formed. On a wet winters day the air between raindrops contains less water than the warm air in your kitchen when the spuds are boiling. This is why modern heat exchange systems drag air into buildings through heat exchangers whilst expelling the internal air. This keeps the temperature up and moisture down. Garages are not heated full time so it pays to insulate well to keep heat in. My own garage had single skin brick walls and a single skin tin roof. Every winter condensation would drip from the roof and the environment was poor. 18 months ago the roof was changed for a modern system of joists, plywood deck 100 mm insulation a second plywood sheet carrying a waterproof membrane. The change was staggering. No more condensation,Pleasant atmosphere and last winter the temperature did not drop below 5 degrees C at any time. When I was working a simple fan heater produced a pleasant temperature. Also the garage remains cool in the summer. What we need to achieve is to keep the air above dew point temperature at all times so condensation does not form. In doing this insulation is paramount. New houses have in excess of 200 mm in their roof, but any voids must be cross ventilated. Colin Ayre
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13-12-2019, 12:04 AM
(This post was last modified: 13-12-2019, 08:36 AM by Jamie.)
But first, I need to get the guttering up and the waterproofing on the outside. The driving rain is clearly seeping into the tantalised timber. It is frustrating because t cannot waterproof it while it is wet and don't want to insulate it either until it is thoroughly dry inside.
Unless there is some magic waterproofing product which can be used on damp wood and is effective. Somehow, though, I imagine that this is wishful thinking.
Jamie.