Jonny on the pillars of a healthy home

Published 27 August 2015

Many Wellington homes suffer from weeping windows and musty damp conditions.

For many of us the solution might be to invest in a ventilation system to blow dry air from the attic into the home as an attempt to blow the moisture out of the building.

These can work however there are side effects not often discussed and there could be simpler methods to deal with internal moisture issues before looking to complex mechanical solutions.

Here’s my top tips of what to try before investing in a ventilation system:

1. Install a ground vapour barrier below the home: exposed soil could be breathing up to 35 litres of water a day into your home. By installing thick black polythene on the soil below the home will prevent this moisture from evaporating into your home. It’s supplied and installed from $8 per metre and does an amazing job at drying a home.

2. Drying washing indoors can release up to 5 litres of water per load into the home. This moisture sits on the walls and carpet where it helps heat leak away from the building. If you have to dry clothes inside quite often it may be a good idea to invest in an externally vented dryer. This is a controlled use of power that will ultimately help you create a warmer pad. You can even buy moisture sensing dryers to reduce power consumption.

3. Bathroom extraction is key. A bathroom should have an extractor at least 125mm in diameter that is vented to the outside of the home. Be sure to use it every time you shower and keep the bathroom door closed after showering to stop the steam moving into the rest of the house. If one can’t be installed ‘shower domes’ are often help cap steam. Running a wall mounted bathroom fan heater during the shower will also help prevent the steam from condensation on colder surfaces. The bathroom extractor can then remove even more steam while it’s airborne.

4. Heat your home! Condensation occurs when the air temperature is so low it can no longer support the moisture it holds. This results in moisture dropping out of the air and condensing on colder surfaces such as un-insulated walls and windows. This moisture then acts as a ‘bridge’ for heat to escape so rooms can become even colder. Running regular efficient heating when you can will help reduce condensation and will create a drier home. Bedrooms should be 16C at night and living areas should be 18-21C for best comfort and health. Aim for bedroom heaters with digital thermostats to provide more accurate control and affordable bills. Well planned central heating is also a great idea if you’re looking for a more permanent solution.

5. Insulate the home: if your ceiling insulation is less than a hand-span thick you probably need a top up layer of insulation to retain heat. Heat is your best friend when combatting damp and mould. Likewise floor insulation will also reduce cold air infiltration to the home.

6. Cook with lids on. If you boil and cook with lots of steam and the kitchen extractor sounds like a jumbo jet or you don’t have one then cook with lids. Your food will also cook faster and use less gas/power in the process.

Mechanical solutions can work however if you have damp issues it’s always best to focus on finding the source of moisture and deal with it there. Periodic regular heating is also a must in the battle for a warmer, drier home. If you’re at the stage of making investments into your home it’s often a good idea to book and assessment with a Home Performance Advisor. They can help steer you through the actions your home may need to become the winning comfortable cosy nest it was always meant to be.