is porch roof build causing condensation?

[MartinL276]

Hi
My small porch is getting badly condensated. I was curious to know why and noticed that the soffits had no air vents. I removed the soffits to see what the insulation was like and found very thin insulation sheets (about 50-100mm thick), but also noticed that the insulation is on top of a raised platform (for wiring)meaning an exposed gap of about 150mm between the porch ceiling and the insulation. Is this correct? It seems to me that the cold air entering the porch attic is freely circulating into the exposed gap and cooling the porch causing the condensation (and meaning the insulation is useless). Any ideas on what is the problem and any suggestions how I can easily fix this? Thank you very much

 

[^woody^]

The principles area that air will condense on any cold surface.

So you either
insulate to remove the cold surface, or
ventilate to remove the condensation that may form - which may then promote mould growth.

Condensation itself is not a problem and may never be resolved in extreme conditions of hot and cold.

 

[foxhole]

Insulation is only of use if the porch is heated, if not good ventilation is required to keep it dry and mold free.

 

[noseall]

any suggestions

Lower your expectations or build a more robust 'proper' extension.

 

[MartinL276]

Thanks for your help.... I'll improve the insulation and heating.
Merry Christmas!

 

[^woody^]

It's no good heating a porch, as you could make condensation worse whilst wasting your time and money into the bargain.

Heat, or more specifically a higher air temperature in the porch is causing the condensation now, you don't want to make that any worse.

If you could get some insulation into that void above the plaster board that would often solve the problem. Or get the existing insulation to drop down.

Otherwise, getting some ventilation into the porch would help.

Paint the ceiling with a specific kitchen and bathroom paint. These are often incorrectly named "anti condensation" paints. They don't stop condensation, but they do resist mould more than normal emulsion and make the ceiling wipeable. Or a gloss paint - satin if you would not like it to be glossy.

 

[noseall]

I wasn't intending to be curt, but, as is often with this type of building, is that the problem just gets moved to another location until you have took everything apart and insulated and ventilated the bejezuz out of it. Every little helps I guess.

 

[MartinL276]

I'll be insulating it and making sure it's ventilated. Thanks for all of your help.