I have some excellent tenants who have done just this, and I am glad to have them back in one of 'my' properties. If you are looking for tenants at this time of year, I'd like a dollar for every one that asks 'is it damp?' or 'is it cold?' (yet another way to make $ from property!). While you can clean up the tell tale signs of condensation and mould with bleach and a mop, it is certainly best to tackle these things at the source. I imagine some readers are thinking 'yep, get rid of tenants who don't open the windows, and dry their clothes inside'. Yes, some tenants seem to contribute to damp houses more than others. But, it is far easier to make the house easy to live well in. How?
When warm air, (laden with moisture from showers, breathing, drying clothes and cooking) meets a relatively cool surfaces (such as windows, ceilings and exterior walls) droplets of condensation form. This provides a nice home for mildew and mould, and also ruins windowsills, curtains, and paintwork. To avoid this, get rid of both the moisture and the cold surfaces for it to form on.
Getting rid of moisture is relatively easy, and arguably the cheapest option. It can be divided into 3 categories - prevention, passive extraction and active extraction. There is one more trick to preventing moisture issues too, and that is insulation.
With prevention, education is the key. I usually leave a brochure on the subject in my rentals for the tenant to discover and (hopefully) read, or include it in their 'welcome pack'. While doing the initial inspection, I say things like 'the previous people found opening the kitchen window when they did the dishes saved them having to wipe the condensation off the window afterwards', to make new tenants aware of potential moisture build-up problems and remedies.
Passive extraction you will know by its more common name, opening a window. Some tenants never seem to open windows. If you ask them why, it is usually a security issue. Make windows more secure to leave open with opening restricting devices, such a securi-stays. It is most important that these are installed correctly and are working well, but remember no open window is completely safe. Even more important is that the windows themselves function well – nobody wants to slit a wrist trying to nudge open a stubborn window. There are window specialists that will tune your windows so each functions perfectly once more, and fit security devices while there. They can also fit weather-strips to doors and windows to prevent rain and drafts getting in. Worth considering.
Active extraction is the next step. These generally cost more to install and for the tenant to operate. So if your property appeals to the budget conscious, deal with passive extraction first. Active extraction is essentially fans. Using fans to draw moist air out from bathrooms, laundries, and kitchens can help moisture issues considerably. You can use the cheapest of fans, or the fanciest of DVS systems, and you will more or less get what you pay for. Keep to the style of your building - a top-of-the-line heat pump will not turn your sow’s ear into a silk purse. Likewise, don't spoil your executive retreat with an 'expel-air' through the kitchen window!
With fans and ducting, there are a few simple design rules to help get the most out of it.
- Straight ducting works better than one with bends (and smooth tubes work better than crinkled) so plan positions of ducting carefully.
- Put the outlet (exterior duct) away from inlets (i.e. windows) to prevent the moisture coming back in the short way.
- The closer the duct is to the source of moisture (e.g. over the shower) the drier the room will remain.
- Putting fans on a timer switch will help clear moisture even after the room is vacated. The longer the fan runs, the more moisture should be removed. Your electrician should be able to do this easily.
I could write a book on lifestyle changes to prevent moisture problems, but here we are concerned with 'tenant proofing' your building. Insulation is easiest to do when building or during major renovations, so developers take note. Un-insulated surfaces transmit heat from outside to inside, and vice versa. If you have moist air inside, this will condense on the coldest surfaces. Most notably, this is the windows, but you may have also seen signs of moisture on lower exterior walls, especially in south facing rooms. These colder exterior walls are also taking heat from a room, so more heating is required. When the heating is provided by portable gas heaters, you have more moisture being put into the house – paradoxically, when natural gas burns it produces water. Moist air is harder to heat than dry air, so requires more heating to feel warm, so more moisture.. (Incidentally, thanks to the landlord who was inspired to put 'no gas heaters' on a tenancy agreement, I too have successfully used that for my own properties). Tenants who are cold in a mouldy house will leave, and you will have a cold, damp house empty in winter - not my favourite time to find tenants.
How do you get rid of those cold surfaces? By insulating. Ceiling and under-floor should not be too much of a problem in existing older houses. There is a myriad of options for materials and installers (some offering very good 'specials', especially if your tenants are beneficiaries). Walls can get loose insulation blown into them via some reasonably unobtrusive holes cut here and there, though it can be expensive. Insulate walls with batts when you re-clad the inside or the outside. It is an extra cost, but it pays itself back.
Let’s do the sums. If I insulate the ceiling of a property myself for $1000 in materials, and I rent the property for $250 per week, I need only save myself 4 weeks of vacancy to reach break-even point (And if the property rents for $500 per week, it probably will still cost around $1000 to insulate). This may happen in just the first winter. I could even use the insulated ceiling as a selling point if similar properties lack it, and ask slightly more in rent (let’s not be greedy, say $5 per week). This gets me another $260 per year so in just 4 years I have certainly recovered my cost. Not a bad investment.
For windows, if you are building, please consider double glazing. The proportional extra cost on a building is minimal (about 1%) compared to the benefits. If you have an existing building with single glazing, you can get 'secondary glazing' or 'winter windows' that fit over the existing window units. A cheaper option is applying a plastic shrink-wrap film - not durable, but great while it lasts. A more common solution is to install thermal curtains.
Curtains are a great way of adding warmth to a property. This can be achieved pretty cheaply if you search bargain bins, or my favourite, end of line material (and because it is a rental, your sense of taste should not go 'out the window' – you need to 'sell' your property to tenants). I have picked up many a roll of $25/m fabric for just $2/m. It helps if you have the time and skill to make the curtains. The best warmth retaining curtains have two layers of fabric, one of those being thermal. They also cover the entire window, and preferably a good portion of the wall around it. Floor to ceiling curtains are great, even for small windows, especially with a pelmet to stop warm air dropping behind the curtain rail (although pelmets are not 'in' at the moment – try painting the same as the wall colour to blend in). Curtains with a lot of gathers are a lot warmer than ones that are straight when pulled shut. Buy or make curtains at least twice as wide as the window they are to fit, gather up the pleats with the pull cord, and hang with a lot of hooks. Put the last hook through the cap at the end of the rail in a way that curves the curtain back to the wall and prevents heat and light from spilling around it. Not only do well hung curtains retain warmth better, they look better too. When you are letting a property, you have just one chance to make the first impression. In winter, aim for 'warm' and 'dry' to be that impression.