Tips for measuring humidity

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bparekh
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Tips for measuring humidity

Post by bparekh » Thu Apr 20, 2017 12:24 am

Hi

I have a tenant who regularly complains of mould appearing in the rooms downstairs. The specific wall is the gable end of a 1900 row of terraces.
When I go in to inspect I feel that the house is very humid, which I think is not correct and not helping the mould.
I could be wrong but I am judging this on the difference in being inside the house compared to outside.
I want to leave him a meter to measure humidity.
Any recommendations?
Thanks

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michaelp
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Re: Tips for measuring humidity

Post by michaelp » Thu Jul 13, 2017 9:59 pm

Hi
I have several humidity testers.

Two of them are german TFA hygrometers - one analog, one digital - bought on Amazon. I use them for reference and calibrating of all the cheap ones.
Many cheap ones (£1 - £2 apiece), I bought on ****** and ebay. Most are very close with the readings to the TFAs - within 3% RH 'out of the box'.

I put all the devices around the house and this helps to reveal damp spots.
For example, in a room: 60%RH on a table, 75% on a window ledge, 85% on the floor by fireplace. This helps pinpoint penetrating / rising damp / lack or faulty damp membrane etc.

I also use damp tester - device with two metal prongs which need to be pushed into masonry or wood. This one is particularly useful when detecting rising damp and effectiveness of raising damp course. You can test a wall at different heights to determine which way the moisture spreads. If you do it after a heavy rain you may detect the cause of a problem right away.

Good luck!
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Re: Tips for measuring humidity

Post by multiman » Sat Jul 15, 2017 10:00 pm

I have one of those damp tester with prongs very useful for damp testing

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Re: Tips for measuring humidity

Post by Barry_Convex » Thu Jul 20, 2017 7:24 am

Those 2 prong testers are said to be completely useless in masonry because they also give a reading in the presence of salts so give many false positives.

They're designed for timber.

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Re: Tips for measuring humidity

Post by bparekh » Thu Jul 20, 2017 3:33 pm

Hi. Thanks for the responses. I guess once I find high levels the answer could be ventilation. They don't like keeping the windows open hence the problem. Esp during colder months.
I have put extractor fans in 2 rooms but I think they are extracting enough (or they are not switched on - I can't tell).
Is there any better solutions/products that can be installed.

Thanks

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Re: Tips for measuring humidity

Post by Barry_Convex » Fri Jul 21, 2017 11:52 pm

Humidity and it's consequences are a minefield for landlords (and indeed homeowners). The rising cost of heating fuel has created a wish for all properties to be air tight under the assumption that it will save money. But this creates maintenance problems for the fabric of the building, which didn't have to deal with trapped humidity when it was first built.

Assuming there are no real external damp problems (gutters, window seals, floor vents, rising damp) then internal moisture created by the occupants must be allowed to leave the building. Occupants should be made aware of this situation and given guidelines to help resolve the effects as well as you fitting devices.

Firstly create less humidity :
Use lids on boiling pans.
Don't dry clothes indoors. (at least not in closed rooms)

Secondly allow moisture to escape :
Use extractors when available (especially kitchen and bathroom).
Keep window trickle vents open all the time.
Keep air bricks open.
Leave internal doors open frequently.
Vent any bricked up fireplaces.

Humidistat extractors are good and can be set to keep extracting until the humidity is down to say 50%. But a tenant can always switch off the isolator - make sure they know that mould is partially their responsibility.

A further option is an active loft vent. It pushes warm, dry air into the property from the loft which pushes moist air out. It retains heat better than regular venting. Can't remember the name of the products off the top of my head though.



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Re: Tips for measuring humidity

Post by multiman » Sat Jul 22, 2017 12:14 pm

A positive input ventilation in loft will reduce damp

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Re: Tips for measuring humidity

Post by multiman » Sat Jul 22, 2017 12:15 pm

See this link for more information v

http://www.nuaire.co.uk/our-products/Re ... ts?pt=1685

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