Venting extractor fan through flat roof?

[kkk777888]

Please can you advise a single mother who doesn't know much about houses? My house is a 1930s semi with finished loft that was done before I purchased the home. The Old extractor fan in the loft bathroom was shot so I called an electrician to install a new one and he discovered that it was just venting into the small space between the ceiling and the flat roof with no duct whatsoever! I've contacted a couple of roofers. One didn't seem to know how to manage it and didn't want to. He said that he didn't want to put a hole in the roof and maybe I could run it out through the fascia but didn't want to do it himself and I should find a builder. The other told me that it's better to run it through the flat roof with a mushroom vent and he would do it for £1100. From the advice I can find online it seems that running it through the flat roof really is the better option? Is £1100 a fair price? The roof is accessible by a ladder so no scaffolding required. Thanks for any help you can give!

 

[noseall]

Please can you advise a single mother who doesn't know much about houses? My house is a 1930s semi with finished loft that was done before I purchased the home. The Old extractor fan in the loft bathroom was shot so I called an electrician to install a new one and he discovered that it was just venting into the small space between the ceiling and the flat roof with no duct whatsoever! I've contacted a couple of roofers. One didn't seem to know how to manage it and didn't want to. He said that he didn't want to put a hole in the roof and maybe I could run it out through the fascia but didn't want to do it himself and I should find a builder. The other told me that it's better to run it through the flat roof with a mushroom vent and he would do it for £1100. From the advice I can find online it seems that running it through the flat roof really is the better option? Is £1100 a fair price? The roof is accessible by a ladder so no scaffolding required. Thanks for any help you can give!

We vent through the roof tiles often, but it will depend on what type of roof tile you have along with accessibility etc.

Raisedtie6

• noseall
• 15 Mar 2019

Multis

• noseall
• 6 May 2020

 

[^woody^]

Venting through a flat roof would be the highest risk and least preferred option. Are there other possible options for siting the fan and running the duct?

There will be costs involved in working at high level and messing about with ducting and vents, so you will be charged a premium for that. You'll need to decide on an option first and get several quotes based on that, not lots of quotes all quoting for different things.

Bear in mind that whoever does this needs to know what they are doing. The type of fan, the type and positioning of ducting, the external terminal or grill all matter.

For the fan. if you have any mould or condensation issues, consider a low voltage (SELV) fan with continuous and automatic boost plus humidistat control. Otherwise, a model that runs off the light or shower switch and has at least 15 minutes overrun is the most basic you should fit