Positive Input Ventilation

[b21playa]

Hi all

Had damp people around who checked RH to be 65% @ 22degC and suggested a a Nuaire Drimaster heat for the sum of £1000 fitted.

Looking around these are much cheaper.

Are these easy to fit, or are there any alternatives?

Need to get one fitted as tenants are complaining about mould on walls in bedrooms

Thanks

 

[dishman]

Ok....before I start my damp rant....

1. Where is the damp located inthe house and where specifically on the walls?

2. What type of property is it?

3. Are the walls insulated?

4. Does it have upvc windows? Do these have trickle vents?

5. How long have the tenants lived there? What type are they (young professionals, students etc.)

6. What ventilation solutions are in the property already (Air bricks, Bathroom extractor fans etc.)?

7. Is there a tumble dryer? Do the tenants use it?

8. Is there central heating? Do your tenants dry clothes on there?

Please answer these questions before you possibly waste money....

 

[kbdiy]

Do they dry their washing indoors and not open any windows for ventilation?

I ask only because I visited a house to carry out a EPC some while ago. The tenants had the heating running at full chat, the place was full of damp washing and they were complaining about condensation. Needless to say there was not an open window to be seen.

Just thought it worth asking before you shell out loads of hard-earned wedge.

 

[b21playa]

Ok....before I start my damp rant....

Please answer these questions before you possibly waste money....

Thanks for the reply dishman, please see answers below

1. Where is the damp located in the house and where specifically on the walls? Front bedroom in the corner and on the carpet, bedroom ceiling in the cupboard

2. What type of property is it? Extended semi detached with cavity walls

3. Are the walls insulated? retro cavity insulation

4. Does it have upvc windows? Do these have trickle vents?Has upvc windows all round but no trickle vents, but windows are left open on 2nd lock

5. How long have the tenants lived there? What type are they (young professionals, students etc.) They have lived there for 6months, and they are an older family (youngest 18yo)

6. What ventilation solutions are in the property already (Air bricks, Bathroom extractor fans etc.)? No air bricks above floor level, but has kitchen and bathroom extractor

7. Is there a tumble dryer? Do the tenants use it?Tumble dryer is in the utility, and always run with back door open, and door to kitchen closed

8. Is there central heating? Do your tenants dry clothes on there? Central heating is present, and in the first week they dried clothes in the kitchen, but this has now stopped after I pointed this out

 

[dishman]

It sounds to me like a sledge hammer to crack a nut solution.

It may indeed help/work. But the cost/benefit is quite high when much easier, simpler changes should work, as well as educating the tenants.

The areas of mould sound like common problem of lack of ventilation and air movement. Corners of rooms and back of cupboards are common areas for this problem.

Any furniture needs to be moved back from these areas to create more "breathing room". Similar with stuff shoved into the cupboards.

A family can produce more than 15 litres of water vapour on a daily basis. The more people insulate and "seal" their homes, the more this water vapour is trapped inside. It no longer condensates on warm upvc window surfaces but now settles on cold spots on the wall.

Follow up questions:

Does the tumble dryer vent outside or is it a condenser? Or does it just vent into the room with the open door?

The bathroom extractor. Is it controlled by the light? Does it go off as soon as the light goes out or continue for a while after? How powerful is the fan? Is it a an old one or quite new?

Did this problem arise more during winter? Heating control can have a large impact on condensation creation. Better understanding and use of heating controls can help a lot.

How do you know the tenants keep the windows on the night vent lock?

 

[dishman]

Just as a follow up: My opinion is that you would be wasting your money on a solution which is not guaranteed to work.

If you read some unbiased studies as to the benefits on PIV; many conclude that there is only a benefit in the very worse case scenario i.e condensation dripping down windows and black mould in every room and all over the place. These were usually poorly built/designed council houses from the 60s/70s with very poor heating provision and insulation.

In properties with small amounts of mould/damp they [PIV] did not have much of an effect.

In any case, to ensure PIV works effectively you would have to do all the things that would probably solve your condensation problem for free!

You have to ensure air can flow around the property, keep internal doors open. Reduce the amount of moisture you create or remove it as close to the source as possible. Use heating more effectively etc.

From experience, homeowners with damp problems seem to like to believe the worst case scenario first and attempt to fix the problem by throwing cash at it in the misguided belief that it will fix it.

In the majority of damp cases, the solutions are usually either free (changing living habits) or quite cheap.

The problem is people do not like to believe/admit that they are the cause of the problem they are trying to solve, nor do people like to change they way they live.

This is usually magnified when the property is lived in by tenants. They just want to live in the property. If there is a problem with the property, it is the landlord who needs to fix it. You as a landlord do not have the ability to change their living habits. As it is not their own house, they are less likely to change their living habits to prevent a problem.

I would print of a guide such as this and explain to them that they need to look at how they use the property.

http://www.bolton.gov.uk/sites/documentcentre/Documents/Condensation and Mould.pdf

Ensure that the extractor in the bathroom is powerful and has a humidistat which will insure it will not turn off until the humidity is at the correct level. If you can, install one in the kitchen too! Ensure your tumble dry vents outside! If a condenser, put an extractor fan in that room as well.