Installing bathroom fan in existing hole

[trojan0852]

I am installing a bathroom extractor fan. There is an existing vent hole in the bathroom wall (rectangular, about 4 bricks volume, with metal grills inside and out). I want to fit the fan in this rather than make a new hole. And I want to retain the external metal grill so as not to change the external appearance.

I've removed the internal metal grill and made a wooden faceplate to cover it. What I can't decide about is how best to fit the fan in the hole - just fix it into the faceplate and leave it at that (blowing air into the vent hole and out through the external grill), adding some pipe onto the fan to take it right up to the external grill and making a support for that, making something (out of I don't know what) that pushes up against the inside of the external grill, blocking it off except for a hole where the pipe opens?

Thanks for sharing any thoughts,
John

 

[PrenticeBoyofDerry]

Have you thought about cementing it in place?

 

[trojan0852]

Thanks, I think cement's a good option. Do you think it's worth sticking some pipe on it and cementing it, or good enough to just have the fan without any pipe?

 

[PrenticeBoyofDerry]

I would put some plastic pipe through the hole in the cavity, it's normally 150mm pipe. then cement it in, both internal and external wall, its worth placing the pipe just at a slight slope, so falls towards the outside wall, this will help prevent any rain fall, that may enter through the external grill entering the property or the extractor.

 

[trojan0852]

I will do exactly that.

 

[helenk579]

Thanks, I think cement's a good option. Do you think it's worth sticking some pipe on it and cementing it, or good enough to just have the fan without any pipe?

I also think so.