Advice needed

[lee g]

I have a 5ft x 8ft wooden shed on concrete which I use to store my scopes. I also sit inside to do eaa and so it doubles as an observatory as well. Though when doing so the scopes sit outside.

Last winter it got terribly damp inside resulting in mildew. What would your suggestions be to stop this whilst also protecting the scopes from the elements?

I was thinking either ventilation and/or a dehumidifier but was unsure what to line the walls and roof with ie ply wood or some kind of insulation.

I was also thinking of interlocking rubber tiles for the floor.

 

 

[GKA]

Start with ventilation , a couple of wholes on a couple of walls. 

Use something similar to this.

Amazon.com: HHT SRV33271 Outside Air Shield Vent : Home & Kitchen

 

[Clarkey]

I would agree with ventilation. I have a small shower vent fan running 24/7 in my observatory. After very frosty or damp sessions I put a dehumidifier on for a few hours just to dry everything out. (If you do get a dehumidifier, it needs to be a dessicant one. Compressor types do not work in the cold).

[malc-c]

Its just a shed... which by nature is not designed to be a "controlled" environment.  The wood will have a moisture content, especially in damp weather, and this can lead to a damp environment which leads to mildew / mold.  Most of us who added a warm room to their observatories have used insulation in the floors, walls and roof, with a little ventilation, which results in a warmer dryer environment.  Now whilst there is not a lot you can do about the floor, insulating and lining the walls and roof with polystyrene and 4mm ply might be something worth considering.  For now, pick up a couple of map vents like these

Place one low down on the right wall, and the other up high on the opposite wall, this should provide a decent air flow as and warm air rises and some will pass out the upper vent and cooler air will then be drawn in through the lower.

[900SL]

If you can, raise the shed and place a sheet of heavy duty polythene DPM below the shed. This will allow below deck ventilation and help reduce moisture

[900SL]

8 minutes ago, malc-c said:

Its just a shed... which by nature is not designed to be a "controlled" environment.  The wood will have a moisture content, especially in damp weather, and this can lead to a damp environment which leads to mildew / mold.  Most of us who added a warm room to their observatories have used insulation in the floors, walls and roof, with a little ventilation, which results in a warmer dryer environment.  Now whilst there is not a lot you can do about the floor, insulating and lining the walls and roof with polystyrene and 4mm ply might be something worth considering.  For now, pick up a couple of map vents like these

Place one low down on the right wall, and the other up high on the opposite wall, this should provide a decent air flow as and warm air rises and some will pass out the upper vent and cooler air will then be drawn in through the lower.

Also add a vapour barrier between ply and the insulation, to reduce interstitial condensation when occupied/heated? 

[saac]

x 2 on ventilation, get that sorted first before you spend money on insulation, vapour barriers or dehumidifiers.  The more air you have passing through the better. I have a hexagonal roof observatory (converted summer house) which by design has a inch or so open gap between the roof and walls so air flows freely in and out.  I don't use a dehumidifier and the walls are uninsulated, it has been running now close to 10 years and condensation/mildew has never been an issue.  If you plan to use the shed vents I'd position them at both low level and high level to encourage circulation.  Definitely try improving ventilation first and if you still have a problem then turn to the insulation, dehumidifier route.  

Jim 

[Macavity]

My prebuild Observatory arrived in large bits - Walls, Floor, Roof! All to be installed in
one day! No time to place brick/tile spacers, between patio flags and floor sub-frame. 😑
Rising damp/mold was a problem. I sense adequate under floor air circulation helps?

The floor is (allegedly) "waterproof chip", so I placed canonical Rubber Squares on top.
But it got very damp under these! Finally, I removed the "tiles", poured/painted a couple
of coats of Non-creosote (non smelly!) penetrating Fence Paint on the floor... It worked! 😎

N.B. Fence Paint is not strictly for internal use (slightly toxic)! But it ceased to smell when
dry, and I cannot imagine such would be a problem for typical Astronomer exposure...
The key to the "remedial" floor coating seemed to be the *penetration* factor though. 😉

Edited September 9, 2023 by Macavity

[lee g]

Thanks for all your replies it seems then that ventilation is the way to go at least to begin with as it’s not an observatory as such. More of an external storage room for the scopes which doubles as a room to do EAA, keeping warm isn’t really an issue for me so maybe I can do without insulating it maybe I’ll just line it with plywood put some vents in and hopefully this will stop mildew/fungus growing on the optics.