Cellar conversion - ventilation

[d000hg]

I posted recently in another forum about how we've started work on converting our 4x3m cellar. While it's a true cellar it is effectively located at the top of a hill which is presumably why it does not suffer too badly with dampness - penetrating damp through solid brick walls only. The plan is to employ some sort of sealed/tanked solution

I was told that ventilation is one of the key problems to solve in order to prevent mould and mustiness and so on. The cellar actually has 3 ventilation grates: 2 at ceiling height directly to the outside at ground level, and another through to the underfloor cavity in another room.

I note that this does already cause a slight through draught, there is a slight breeze coming from under the next room. It made me think that this might be good to encourage. We had thought to put a constant extractor fan in one of the external vents and I'm wondering if we sealed up the other external vent, this would cause more air to be sucked through from under the next room. My thinking was this air is probably going to be a bit warmer and dryer than the outside air, which would aid with condensation.

Or, I could have the extractor fan and block up both other vents. It's an old house so my thought was THIS would then suck air in from the room above, which is going to be warm and dry from central heating.

Any general advice on ventilation concerns are welcome and my rambling text above but here are some specific questions I am considering:

• Is a continuous fan (e.g. https://www.greenwood.co.uk/product/153/unity-cv2gip) sufficient for airflow? We used these elsewhere and they can be run virtually silent 24/7 or boosted if they detect higher humidity.
• Does the positioning of the extractor fan matter e.g. don't put a fan next to another vent, but try and ensure it is pulling air through the whole space? Seems like it would to me
• Is an additional fan helpful, just to ensure constant air movement?
• Am I right to think having warmer/dryer air coming in e.g. from a heated room above, is preferable?

 

[Bonni]

Well, you need building regs so the building regs inspector will help.

 

[d000hg]

Our local planning department is EXTREMELY slow so I feel we'll have started work before they even tell us how much their fee is
I have a book on building regs and will have a look but in most cases, it is little clearer than the regulatory documents themselves.
In fact our local council guy told us "you only need regs approval when you come to sell" which I'm fairly sure is pragmatic but untrue for law-abiding citizens

At this point just after some general guidance. I want to get the cellar better ventilated even just as a cellar for storage before we start work, so frame answers on that topic if you prefer.

 

[d000hg]

I did find this very old thread on the same topic, I guess the fact I have that vent from another room is why we have a through draught which has prevented major damp issues and mustiness.

https://www.diynot.com/diy/threads/cellar-ventilation.68784/

That thread has a broken link to cellars.co.uk; I think this is the correct one: http://www.cellars.co.uk/cellar-conversions
It looks pretty useful.

 

[Leofric]

What will the converted cellar become ?

In fact our local council guy told us "you only need regs approval when you come to sell" which I'm fairly sure is pragmatic but untrue for law-abiding citizens

That is a load of rubbish and coming from a council official ,well

I have a book on building regs and will have a look but in most cases, it is little clearer than the regulatory documents themselves.

some can be hard going for people who work with them every day
Have you thought of getting a Full Plans Submission prepared for bldg. regs approval before work starts on site

 

[d000hg]

Regarding use, one option is as a music room out of earshot of other people.

Another is to use it as my home brewing area, and actually as a beer cellar.

If that link I posted above is current and correct (?) the usage affects the requirements... Storage Vs work space Vs living space?

 

[d000hg]

Here's a different question. I'm familiar with the concept of tanking etc to keep the room waterproof, but I also know water is extremely good at gaining entry through any crack, or bridge.

Typically you'd insulate walls and in my case the walls are uneven and will need dot'n'dab or a stud wall. When you do this, or even affix shelves to the wall, how do prevent this breaching the waterproof barrier?

 

[SFK]

d000hg,
My tanking was done with waterproof sheets on walls and floor all sealed together.
25mm Wood studs/batons placed at 40cm separation held these sheets onto the wall using self sealing screwed rawl plugs.
Having a loose membrane stops any issues with hydrostatic water pressure pushing a painted waterproofing layer off the wall.

The gaps between the studs were filled with 25mm celotex.
Cables were dropped in from above to sockets down chanels in between the celotex.
And then it was all plaster boarded over, holes cut in plasterboard for sockets.

Cannot full remember how they did the floor, But I seem to remember it being, dug out the old floor put in thick layer of concrete, an then put down plastic sheets that were shaped like egg cartons. This left an air gap between the egg cartons and the concrete. Somehow they tied in the wall liner into this egg carton so that the room is a plastic lined box sitting inside teh old (damp but not wet in my case) basement.

Getting back to your question about shelves, I marked on the chipboard floor where the studs in the wall are so that (when there is no carpet) I can see where to screw heavy objects into. I also hang lighter items on the
plasterboard, being very very careful to never ever use screws longer than 30mm (plasterboard being 12.5mm and stud gap being 25mm) to ensure I do not peace the plastic layer.

If you know you have a heavy object you can ask for wood panel to be screwed between the studs/batons and so behind the plasterboard, so that screws have something to screw into and the load distributed (often done for wall mounted TVs).

My builders did not use this, and I cannot recommend them one way or another, but this link has some nice photos of similar looking tanking products that were used on my basement (I do not have a sump pump):
https://www.sumpsandpumpsdirect.co....MIn-Hh47SP5QIVjLHtCh2FjwMmEAAYASAAEgJAnfD_BwE


SFK