Spotting Weathertightness Problems at a Property Viewing

June 24, 2026 SK Homes

Spotting weathertightness problems at a property viewing does not require a moisture meter or specialist training, just knowing what visible warning signs to look for.

You do not need a moisture meter or specialist knowledge to spot the warning signs of weathertightness problems during a property viewing. Many of the most important indicators are visible to any observant buyer who knows what to look for. This guide covers what to check room by room and outside the building during an open home or private viewing – and what findings should prompt you to insist on specialist inspection before making an offer.

Importantly, the absence of visible warning signs does not mean a property is weathertight. Concealed moisture damage behind monolithic cladding can be significant and ongoing without producing any interior symptoms until it is already severe. This guide helps you identify obvious warning signs – it does not replace a professional pre-purchase building inspection with moisture testing.

Outside the Building

Cladding and Joints

Look for cracks in plaster or monolithic cladding surfaces – particularly at window and door corners, at changes in plane, and at horizontal bands or control joints
Check sealant joints around every visible window and door frame – look for cracking, splitting, gaps opening, or areas where the sealant has pulled away from the surface
Look for paint bubbling, blistering, or peeling on the exterior surface – this often indicates moisture behind the surface driving paint off from behind
Check the base of the cladding where it meets the foundation or ground – is it sitting into the ground? Is there soil or garden mulch piled against the bottom of the cladding?
Look for staining or discolouration streaks running down from windows, deck edges, or roof junctions

Roof and Gutters

Check gutter condition from ground level – sagging, rust, or separation from the fascia indicate poor maintenance
Look for moss or lichen growth on the roof surface
Look at parapet walls (solid walls above the roofline) – are there visible cracks or signs of water tracking from the parapet down the wall below?
Check where different roof planes meet (valleys) – these are high-risk points for flashing failure

Decks and Balconies

Look at where the deck structure meets the building wall – is there visible flashing? Is there staining on the wall below the deck connection?
Check deck drainage – do drains exist? Is the deck surface sloped toward the drain or toward the building wall?
Look at the underside of deck boards for discolouration or softness
Check the fascia boards at deck edges for rot or soft spots

Inside the Building – What to Check in Each Room

Ceilings

Water staining on ceilings is the most visible indicator of moisture ingress from the roof. Look for:

Brown or yellow ring-shaped stains – these indicate water that has leaked through and dried, leaving mineral deposits
Areas where paint has bubbled or cracked
Patches of discolouration near ceiling lights (water can track along wiring)
Staining near chimney bases or in corners of rooms that adjoin exterior walls

Walls – Particularly External Walls

Look for staining at window reveals – the inside face of the window frame and the adjacent wall surface
Check the wall lining at the base of windows – is there paint peeling, staining, or swelling of the wall lining near the windowsill?
Look for mould on interior wall surfaces, particularly in corners and near windows
Check skirting boards near external walls – swollen, discoloured, or lifting skirting boards often indicate moisture at floor level

Bathrooms and Wet Areas

Check grout and silicone sealant in showers, baths, and around basins – cracked or missing grout allows water to penetrate behind tiles
Look at the base of showers for soft or hollow tiles that may indicate water damage behind them
Check bathroom ceiling for mould or staining
Look under bathroom vanities for moisture or staining

Floors

Walk carefully across all rooms on ground floors – soft or springy areas underfoot can indicate subfloor moisture damage
Check vinyl floor coverings for lifting, bubbling, or discolouration at edges – particularly near external walls
Check timber floors for cupping (edges higher than the centre of boards), gaps between boards that were not designed to have gaps, or areas of discolouration

The Smell Test

Your nose is a useful instrument during a property viewing. A musty or earthy smell, particularly in closed rooms, below stairs, in wardrobes on external walls, or under-house spaces, often indicates ongoing moisture and mould. Fresh paint applied immediately before a viewing is sometimes used to mask musty smells – be suspicious of very fresh paint in areas that would not typically be freshly painted.

Red Flags That Should Stop Any Offer Proceeding Unconditionally

Multiple visible cracks in monolithic cladding, particularly at window corners
Multiple failed sealant joints on the exterior
Water staining on ceilings in more than one room
Mould visible on interior wall surfaces (not just in bathrooms)
Soft floors in ground-floor rooms
Musty smell present throughout much of the house
Staining at multiple window reveals inside
Fresh paint over what appears to be staining that has bled through

Any of these findings in combination with a high-risk building profile (1992-2004, monolithic cladding, no eaves) should prompt specialist weathertightness investigation before any unconditional offer.

Frequently Asked Questions

Can I identify a leaky building just by looking at it?

You can identify warning signs and risk factors but you cannot confirm weathertightness status through visual inspection alone. A professional building inspection with moisture testing is required to properly assess weathertightness. Your viewing observations help you decide whether specialist investigation is warranted and at what level.

The house was freshly painted before the open home. Should I be concerned?

Fresh paint before a sale is normal and not inherently suspicious. However, fresh paint in areas that have unusual patterns (paint over stains that bleed through, new paint only in specific corners or wall sections) can indicate an attempt to conceal defects. A professional inspection will look beyond the surface.

I noticed mould in a bathroom. Is this a weathertightness issue?

Mould in a bathroom can be caused by inadequate ventilation (an extractor fan issue) rather than weathertightness failure. However, mould on external walls outside of wet areas is a more significant indicator. A building inspector will assess the likely cause of any mould found during the inspection.

The property is a 1998 monolithic cladding home with no visible signs of problems. Do I still need a specialist inspection?

Yes. The absence of visible symptoms does not mean the property is weathertight. Moisture damage behind monolithic cladding can progress significantly before producing interior symptoms. For a 1998 monolithic cladding home with risk factors, a specialist inspection with moisture testing is strongly recommended regardless of the visual appearance.

What should I ask the real estate agent at the open home?

Ask: Has the property had any weathertightness investigations or remediation work? Is the LIM report available? What is the construction type and approximate build date? Has the vendor obtained a pre-sale building inspection? These questions can be revealing in themselves – a vendor who has a current building inspection report and can provide it shows transparency; a vendor who deflects the question of construction date or inspection history warrants more scrutiny.

Concerned about weathertightness? Book a professional Pre-Purchase Building Inspection with SK Homes NZ Limited. We identify weathertightness risks and moisture issues in Auckland, Hamilton, and Palmerston North properties. Contact us at info@skhomes.co.nz or visit skhomes.co.nz