When a brushtail possum is closed out of your roof, it needs somewhere else to sleep. NRE Tas suggests encouraging possums to stay in the yard rather than the roof by giving them a nesting box or a hollow log. This page covers the department's design guidance, where to put a box on a Hobart block, and how a box fits into a proofing job.
Hobart Possum Removal is a referral service. We do not make or install boxes. With your consent, we pass your enquiry to one independent Greater Hobart business that can supply and install a box, usually as part of exclusion and proofing.
Why a box rather than relocation
NRE Tas explains that relocating possums does not generally work. Another possum moves into the empty territory, and relocated animals often die from predation or competition. A possum that has been shut out of your roof will stay in its home range. Giving it a weatherproof den nearby reduces the pressure on your repairs and gives the animal a safe place to go.
NRE Tas design points
The department's nest box guidance includes:
- Height: place the box 4 to 5 metres above the ground.
- Waterproofing: seal the top edge of the lid with a folded strip of sheet metal, aluminium angle or a rubber flap. An old inner tube will do.
- Eaves: the lid should overhang by about 110 to 120 mm to keep rain out.
- Entrance: directly under the overhang, about 110 to 120 mm wide. It does not need to be round.
- Perch: a sturdy branch screwed to the front is an optional extra that helps the possum get in and out.
- Drainage: four holes of about 5 mm near the corners of the floor.
- Bedding: dead leaves or natural wood shavings for insulation.
- Material: do not use chipboard, which breaks down quickly.
A hollow log blocked at one end is the department's alternative.
Placing it on a Hobart block
- Choose a solid tree well away from the house, so the box does not become a launch point back onto the roof.
- On sloping blocks, measure the 4 to 5 metre height from the ground directly below the box, not from the uphill side.
- Face the entrance away from the prevailing cold westerlies and southerly changes, and out of the hottest afternoon sun.
- Fix it with straps or bolts that allow for tree growth.
- Keep it out of reach of dogs and cats.
How a box fits into an exclusion
Ideally the box goes up before the possum is shut out, so it has a ready alternative on the first night. NRE Tas notes that the scent of a den draws possums back, which is why old entries should be washed with disinfectant or bleach. A box nearby gives the possum somewhere to go instead.
Maintenance
Check the box from the ground once or twice a year. Introduced birds such as starlings, or bees and wasps, sometimes take over boxes. If bees or wasps move in, get professional help. Replace the box once the timber or lid starts to fail.
Building your own or buying one
Many Hobart owners build a box from the NRE Tas plan in an afternoon. Wildlife groups, garden suppliers and some pest businesses also sell them. Whichever you choose, check the entrance width, the waterproof lid and the drainage holes. A box that lets rain in will not be used through a Hobart winter.
If more than one brushtail lives around your home, more than one box may help, because adults usually den alone. Spread them across different trees. If there is no suitable tree, a box can go on a tall, sturdy pole well away from the roofline. Ask the installer what will work on your block, especially on steep or exposed sites.
What it costs
We do not quote. A ready-made box usually costs far less than the removal and proofing work, and many businesses add supply and installation to a proofing quote. Ask whether the box is included, what height and tree are proposed, and whether installation needs a ladder or an elevated work platform on a steep block.
Living alongside possums
Hobart's bushland suburbs will always have possums nearby. A box, a sealed roof and a few garden changes usually let people and possums share a block without conflict. NRE Tas suggests closed compost systems, bringing pet food in overnight, and planting species possums find less appealing, such as prickly grevilleas and hakeas, woody banksias and tea-trees. A possum that is well housed in a box and finds little food near the house is much less likely to keep testing your roof.
Frequently asked questions
How high should a possum box be in Tasmania?
NRE Tas recommends 4 to 5 metres above the ground.
What size entrance does a brushtail possum box need?
About 110 to 120 mm wide, set directly under the overhanging lid.
Will a possum box stop possums getting back into my roof?
Not on its own. It works alongside sealing the entry points and removing access routes. A sealed roof plus a nearby box gives the best chance of success.
Can I take the possum and the box to the bush?
No. NRE Tas says relocation does not generally work, and relocated possums often die. Taking or possessing a brushtail also needs a permit.
Should I put food in the box?
A small piece of fruit can encourage a possum to explore a new box. Regular feeding is not recommended, because it draws more possums and can harm their health.
Can I use a hollow log instead of a box?
Yes. NRE Tas lists a hollow log blocked at one end as an alternative. Mount it securely at a similar height and make sure it sheds rain.
Next step
Tell us your suburb and whether you also need exclusion and proofing. With your consent, we pass your details to one independent Greater Hobart business. See how it works or make an enquiry.