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Tuesday, 31 January 2017

Rubbish Mechanical Extractors

This is what an extractor fan louvre should look like when in operation. I am not sure that I have ever seen this in practice. Wracked my brains, but apart from louvres on commercial systems I cannot recollect ever seeing much more than an occasional feeble movement. Certainly on my home there is rarely more than a flutter.

So if the louvres aren't moving, then the fan is not working properly, but this is the situation with virtually all extractors in the UK. So this in turn means that we are not dealing with ventilation as we should. All the calculations in Part F of the building regs etc are just a waste of time if the equipment we use is just rubbish.

The real life situation is made worse of course if the vents are facing the prevailing winds. With such minor pressure coming from the fans any extracting doesn't stand a chance against any sort of wind. Then we also fit any draught devices that just make it even more difficult for a poor fan to extract the volume of air required to keep condensation down to acceptable levels.

So what to do?

Well, it is worth having a look at a video from Envirovent. This helps to show the effectiveness of different types of fan on the market.

This video looks at standard type fans, but you could also look at a dMEV fans. dMEV are Decentralised Mechanical Extract Vents. These work by continuously extracting air from a localised position (like in a bathroom). There are various manufacturers and types. So you can have more sophisticated ones that work by sensing factors like humidity, so as humidity increases, so the fan will respond according by extracting more air. They can also be controlled by timers & pull switches and combinations thereof.

So, if you have mould etc in your kitchen / bathroom, despite having an extractor fitted, almost guaranteed it would have been the £10 model from the local electrical factors or DIY store. So I would recommend that you look to replace it with a good quality fan that actually works rather than just making some noise.

I will be replacing mine at home very soon. I will have a standard fan in the upstairs bathroom (as this is an ensuite and also made of breathable materials) and a dMEV in the downstairs bathroom that can run continuously. The downstairs room is more prone to mould as it is less well insulated and more heavily used, hence the decision. I will be changing the one upstairs myself as it is a simple case of changing leads over from one unit to the other, but the downstairs one is currently operated by the light switch and so we will need to get a continuous live feed into this. Probably a simple job, but not being a 'sparky', I would prefer the confidence that a professional brings to the task.

So, as ever, it seems like you get what you pay for. So as a special note for people living in older properties. We have spent much of the past decade sealing up houses in the name of energy efficiency and carbon savings. This has meant that many of the sources of fresh air have gone and we are living more and more in warm, humid and still environments. This is not good for your health or for the health of the building. We need ventilation. We need fresh air. We need to remove warm moist air in order to reduce the risk of mould growth. So look to get a good working ventilation system in place at home. This starts with mechanical extract from high risk zones like bathrooms, toilets. kitchens and utility rooms.

Get good fans that actually work.

Wednesday, 18 January 2017

Great News for Lime Lovers

At last the revolutionary lime product that we have all been waiting for:

I have known for sometime that someday, someone (well I knew whom) would create a special lime product that would answer all the concerns that people have about lime on their buildings. Well folks, that day has arrived.

Vivus Solutions have just launched their website to you access to their amazing materials. Have a look at Lime has never been easier, quicker, better. Forget all your prejudices, this is a series of products that can be used by virtually anyone on virtually any old building.

We have known for many years that we have been ruining older solid walled buildings by applying modern non-breathable to them. Almost every traditionally built solid walled house is covered with hard cement render or an impervious paint, walls have been re-pointed with cement mortars that lock in moisture and cause the bricks and stones to spall. This has been due to a large amount of ignorance in the mainstream industry and a lack of awareness from owners. Time and time again I, and many others, have stated that lime mortars and renders need to be used on projects, but clients end up listening to mainstream builders and surveyors rather than conservation specialists.

For years, the industry has moaned about the fact that lime is slow, difficult to use, expensive, unreliable and just out of reach for most. Well I think that this is a game changer.

As well as being an Air Lime (which provides a highly breathable mix) this new series of products are sent out dry. No longer will we have to pay for wet mixes to be delivered. So already it is money saver. The 20kg bags are designed to be mixed up in a standard mixing tub with a plaster whisk.

The small bag sizes are important for two reasons. Firstly Health and Safety but also the fact that each mix will be dry in a day. So you don't want to have it sitting around for long.

Dry in a day! That is truly remarkable for a non hydraulic lime. However, it will still carbonate like a putty over time, so it will still absorb CO2. So the trick has been to get an Air Lime to set this quickly. Great stuff. This means that suddenly you are not there waiting around for days for first sets / coats to dry etc. As I say, a game changer.

I would highly recommend that people have a look at all the products available - there are internal plasters, external renders, mortars and even some pre-formed laths. Spread the news!

Note: We do not benefit commercially at all from this product, or from Vivus Solutions, I just think that it is great.