Select windows with good seals on moving sashes (the glass and frame) and over weep holes. Wind-driven rain can enter through the weep holes in windows and glass sliding doors.

Some windows are designed with features such as ball valves in sills or flaps over weep holes. This is to minimise the volume of water that is driven into the sill by differential pressure from the outside of the building to the inside. Better quality seals do not allow water to bypass them at the ends of the seal. They can also accommodate movement in the window under high pressures.

Installing windows for a higher wind classification is one way to achieve better water resistance.

Ask your builder about the effectiveness of the seals for pressures higher than the standard test pressure. This will give you an indication of the performance of the windows.

Debris rated screens are made from open mesh, so they will let some wind-driven rain through them. These should be tested to the requirements of AS/NZS 1170.2

They're usually permanently fitted to the windows and doors. They need to allow for windows or doors to be opened when there isn't a cyclone. 

Install 14 mm thick plywood shutters on windows and glass sliding doors. This should be done as part of the preparation for an approaching cyclone. The brackets for the plywood sheets need to be installed before the cyclone season. They must be in place so the sheets can be positioned quickly and easily.

The plywood shutters should be pre-cut to size with holes matching the bracket positions. They should be clearly labelled so that they can be installed in the correct location and orientation. They should be stored in dry conditions and easily accessed when needed.

For higher windows and doors, ladders may be required to install the sheets. Safe work practices should be used to lift the sheets into place and secure them.

This type of action is appropriate for glass sliding doors where permanently mounted debris screens may make accessing the door difficult.

Water can get through windows and glass sliding doors through the seals. These seals move as the window flexes under high wind pressure. It can also enter through weep holes that are designed to let condensation out. 

Installing a plastic sheet catches water that has been blown around seals and through weep holes during peak gusts. It holds this water so that it can flow out through the weep holes during lulls in the wind gusts.

Leaves and other vegetation can build up in gutters. During a cyclone, blocked gutters can allow rainwater to overflow into eaves. This can damage eaves linings or flow inside the house and damage internal walls.

You should make sure that gutters, rainheads, downpipes and overflows are free of debris. Before a storm, check they're flowing correctly. 

Reinforce your gutters by installing gutter clips at closer spacings than specified by the manufacturer.

Gutters are clipped onto the edge of your roof. Extreme wind loads can unclip gutters and cause flailing. This can damage the rest of the building and lead to concentrations of rainwater that can get past flashings and cladding and enter the roof space.

Roof sarking is a strong and pliable membrane that can be installed under tiled and metal roofs. It is usually made with a reflective foil layer on one or both sides. It may be possible to install sarking in an existing roof if you are doing major renovations or home extensions. For example, if a tile roof is being re-tiled, it may be possible to install sarking before the new tiles are installed. The best time to install sarking is during the construction phase. This is because it needs to be installed directly below the roofing material.

Sarking also protects the exposed frame of your house from dust, wind and rain during the construction phase.

Sarking improves the sealing of the roof from wind-blown hazards. This includes wind-driven rain in tropical cyclones if the sarking is water-resistant.

Solid-core doors are more resilient to damage from small and light wind-borne debris than hollow-core doors.

If doors blow in during strong winds, water can enter the building through the large door opening. This water can cause damage to linings, internal cabinetry and building contents. Doors can fail by flexure of the door itself or by failure of the latch or hinges. If the latches or hinges are too small, they cannot resist the wind pressures and would be the weak link in the door.

Standard entrance door locks may not be adequate to withstand cyclonic wind loads. This is particularly true for double doors. Additional support for external doors, such as bolts into the floor and head of the door frame, may be required. For double-opening doors, bolts on top and bottom are required on each door panel, as the central latch cannot provide sufficient strength to keep the doors closed.

Flashings are thin sheets or strips of water-resistant materials. They are installed at the intersections of roofs or walls and around windows and doors. They help to direct rainwater flow away from the building. Flashings must be fastened securely with closely spaced screws. The maximum spacing for screws is 500 mm for most flashings. This is outlined in AS 1562.1, the Australian Standard for the design and installation of metal roof and wall cladding. They should be secured so they can’t be lifted or blown off your home by wind.

Penetrations and openings in the roof cladding can create edges that must be sealed. This includes openings for aerials, air conditioners, skylights, and whirly birds. This will help seal against wind-driven rainwater in storms and tropical cyclones.

Where flashings tear or are lifted from the building, then wind-driven rain can enter the building. This means plasterboard ceilings can get wet and potentially collapse. Ensuring that the flashings are well anchored to the building can help minimise the amount of rainwater entering the building.

Openings in the building envelope (windows and doors) have seals to be almost air-tight when closed. If these seals are water resistant they can keep out wind-driven rainwater.

You should check the seals on windows, glass sliding doors and swinging doors regularly. If they are worn or damaged (broken, torn or misshapen) you should repair or replace them. Swinging doors should have seals at the bottom, sides and top.

Debris can break glass windows and doors and create an opening in your building envelope. This opening can increase the internal pressure of your home and can also allow water to enter the building.

Internal pressure can increase the structural loads on the connections of your home, which can damage the structure. Rain water can damage floors, walls and contents.

You should consider installing a wind-rated roller shutter. It may not prevent windows breaking but can reduce the size of the opening. This can help keep wind pressure and rainwater out of your home.

Wind shutters are a permanent addition to your home which may also function as security or blackout shutters.

Wind-driven rainwater can enter your roof space, particularly if it is falling at an angle. Even with effective flashings and gutters this can cause damage to your ceilings, wall linings, and home contents.

You should consider installing closed cell foam between your roof and flashing. This can prevent water moving into the roof space.

You should upgrade your metal roof cladding and flashings. They should meet the minimum requirements of AS 1562.1. If you are replacing a tile roof with a sheet metal roof then the roof structure will also need to be upgraded. This includes needing to strengthen tie-downs as metal roofs are lighter than tiled roofs.

Flashings are thin sheets or strips of water-resistant materials that are installed at the intersections of roofs and walls. They are often metal and can direct rainwater flow away from the building. Flashing should be fasten securely with closely spaced screws, with a maximum spacing of 500mm. Flashings should be securely fastened so they can't be lifted or completely blown of the building by wind. This aligns with AS 1562.1 standards.

There may be openings in your roof cladding for items such as aerials and air conditioners. These edges must be effectively sealed to avoid wind-driven rain entering. Sealant can deteriorate in the sun. If it is cracked or has pulled away from the flashing it should be replaced.

If flashings tear or are lifted from your house then wind-driven rain may enter the building. This can result in plasterboard ceiling getting wet and collapsing. You should ensure flashings are well anchored to the building to minimise the amount of rainwater entering the building.

Overflows in eaves gutters are large holes (>20 mm diameter) that direct excess rainwater away from the roof space. Smaller overflow slots stamped into gutters can become blocked by leaf matter.

When your roof gutters overflow, it is likely that water will flow into your eaves, inside your ceilings and internal walls causing considerable damage.

Your roof gutters may overflow if:

• gutters have become fully or partially blocked
• gutter design and installation is not suitable for your circumstances
• gutters and downpipes are not large enough to carry the volume of water flowing from the roof
• there aren't enough downpipes or they aren't in the right places
• insufficient fall to the downpipe
• there is very heavy rainfall that is more than your gutter system can cope with
• there is wear and tear or other damage to gutters

Note: The overflow holes in the front of metal gutters may not be effective. They often get blocked by leaves and debris.

Valley gutters can allow wind-driven rainwater to enter your roof. This is especially true when wind is blowing up the valley, as the shape of your roof may concentrate water in the valley.

You should avoid designing complex roofs that have many valleys and ridges. Complex roofs need greater protection to prevent rainwater entering your roof during a storm or cyclone. You should instead choose a simple roof profile. This stops the need for complex sealing of the side and top of the valley gutter against the rain.