Sometimes – like when the area has strict height restrictions — flat roofs are unavoidable. But more often than not, they are an intentional design feature.
For example, a home can be designed with a flat roof to achieve a particular architectural appearance (inside and outside). Maybe the homeowner wants to utilise the roof space for an entertaining or garden area. Or perhaps it’s a case of economics (flat roofs use less material and can therefore be cheaper to construct).
With the growing popularity of flat roof homes, many Adelaide Hills homeowners are suffering issues with condensation and mould.
Why So Many Flat Roof Homes Have Moisture And Mould Problems
All homes emit hot, moist air into the roof cavity (through bathroom exhaust and through general living). This air rises through the cavity and collides with the inside of the roof above. When the temperature of the roof is colder than the air, condensation can form. Without proper ventilation, this condensation can cause mould to grow throughout the roof cavity and even penetrate the gyprock in your ceiling. Excess moisture can also cause timber rot or steel rust in the structure of your home. The result is an unhealthy home that can become structurally unsound.
Traditional, high-pitched gabled roofs have large roof cavities (space above the ceiling). This offers more drying potential as a result of either the ventilation of the space, or management of moisture via high performing building membranes.
Flat roof homes have much smaller roof cavities with less air movement and less chance to dry the air before it condenses on the inside of the roof. This greatly increases the chance of moisture, mould, and (over time) structural damage.
How To Avoid Moisture And Mould In Flat Roof Homes
The easiest way to avoid moisture issues is to design your home with a steep pitch and a large roof cavity. Most homes that are a hundred or more years old have high roofs. They last a long time because the air in the roof cavity has time to dry out (without condensing) and therefore there is no mould, and the timber structure remains dry.
If a flat roof is unavoidable (because of height restrictions or architectural preferences), there are things you can do to minimise moisture issues. The addition of extra building membranes inside the roof cavity (on top of the ceiling and underneath the roof) reduce the transfer of heat and moisture. Installed properly, this can greatly reduce (and even eliminate) moisture issues in flat roof homes.
The Cost To Avoid Moisture Issues In Flat Roof Homes
The cost to fix moisture issues in a home (especially a flat roof home) can be huge. And in some cases, the problems simply cannot be fixed. However, precautions (like extra membranes) that reduce and, in most cases, eliminate these issues, can be installed for just $4,000-$6,000 depending on the size of your home. If only Adelaide Hills flat-roof homeowners had known this, they could have avoided the moist issues that compromise their health and the longevity of their homes.
Free Expert Advice To Ensure You Get A Mould-Free, Condensation-Free, Healthy, And Comfortable Home (Even If It Has A Flat Roof)
Avoiding moisture issues in a flat-roof home requires specialised knowledge and experience in design, product choice, and installation.
Whether you’re ready to build or still looking at your options, one of the best things you can do is pick up a copy of our special report, The 5 Key Skills of an Energy Efficient Builder. we’d be glad to show you examples of homes that we’ve built to last. We’ll go through the design elements, workmanship details, and all the costs (and options) with you.
