Roof Home Inspection
For the home inspector, checking the condition of the rooftop and the roof cavity is almost always the most critical part of his/her inspection. The roof and roof cavity are the areas of the property where serious defects are most likely to be found. These are also the two areas of a property least accessible to the laymen (buyers, sellers or owners of the property).
Flashing is the waterproofing used in areas where the roof intersects with walls, roof projections and other roof plans (valleys and ridges).
- Here are some of the common defects for the inspector to look out for.
Monitor the flashing and joints around all roof penetrations, including drains, sewer vents, chimneys, skylights, antenna mountings and other roof-mounted elements.
- Check to see if metal flashings need painting or re-anchoring and if bituminous or acrylic flashings are brittle or cracked.
- Check for missing flashing (waterproofing) at the intersection of the roof with headwalls, sidewalls and parapet walls.
- Check parapet wall flashing and waterproofing of the tops of the parapet walls.
Tile, slate roof coverings
Here are some of the common defects found on tile and slate roofs:
- Cracked, broken or dislodged tiles or slates
- Curling fibre-cement slates – evidence of moisture absorption.
- Cracked mortar bedding on the roof ridges and verges
Metal roof sheeting
Metal roof sheeting comes in a variety of profiles (corrugated, IBR, Kliplok etc) and may be galvanised sheeting (painted or unpainted) or factory pre-coated sheeting such as Chromadek or Colorbond. Older metal sheeting should be monitored for rust especially in the overlap areas.
Asbestos and fibre cement roof coverings
Many older roofs of South African homes are clad with corrugated (Big Six profile) or ribbed (Canadian profile) asbestos sheeting. The installation of new asbestos roofs is now illegal, but existing asbestos roofing may be retained so long as it remains in good condition.
Concrete roof slabs
Regular maintenance and periodic inspections for concrete slab roofs are necessary. Problems in low-slope roofs are common and more difficult to diagnose than pitched roof problems because the path of water leakage through flat roofs is often quite hard to trace.
- Watch for signs of ponding water (or puddle formation) on the surface due to improper drainage.
- Check for blocked outlets.
- Check the bituminous torch-on waterproofing for signs of cracking or delamination.
- Check for signs of rotten or loose thatch.
- Check that the thickness of the thatch is at least 175 mm. If the stitching twine is visible from the top then the roof is urgently in need for rethatching.
- Check for visible damage to the hips, ridges and valleys.
- Note any low-pitch thatch roofs – less than 45° (350° for dormer window roofs).
- Note if the current fire safety distances for thatched roofs from boundaries have been violated. Thatch roofed structures (area greater than 20 m²) must be at least 4.5 m from the boundary. Lapas (area maximum 20 m²) may be located minimum 1 m from the boundary. Note that because National Building Regulations are not retroactive, older thatched structures which do not comply with these fire safety distances will probably still be legal.
There are four main aspects of the chimney which the inspector should check:
- The flashing and drainage around the chimney.
- The “crown” of the chimney – is it waterproofed and appropriately sloped, or is water ingress into the chimney and its masonry a threat?
- The condition of the “cowl” – if a cowl has been fitted.
- That the height of the chimney is compliant with SANS 10400-V: 4.3.6.
A leaking skylight is fairly common in roofs where skylights have been installed. From the exterior examine the glazing and seals for cracks or breaks, loosening of the flashing, and rusting or decaying frames. Skylights should be checked from the interior, too.
- Check for blocked valleys and other internal roof gutters.
- Check for broken, leaking or sagging eaves gutters.
- Check downpipe brackets, leaking joints.
- Check that water flow from the downpipes is channelled away from the base of the walls. Downpipes should be fitted with “shoes” directing the waterflow into concrete channels or onto an impervious apron sloped away from the structure.
What to inspect inside the roof cavity
- The general condition of the roof structural timbers.
- That the trusses are sound – no broken, bowed or out of plumb timber members.
- The roof anchoring.
- The roof bracing.
- Fastening systems – splices, nailing and clips.
- The condition of the under tile membrane if present.
- The geyser installation and support platform.
- Visual observation of the electrical installation within the roof cavity – are there loose or bare wires or open junction boxes for instance.
- Visual observation of the plumbing installation within the roof cavity.
- If the inspected building is a residence with an adjoining garage then the inspector should check that a fire wall between the habitable rooms and the garage extending to the underside of the roof covering
- The condition of the roof insulation and/or roof ventilation system.
- The presence of any pests – bird nests and dung or rodent droppings.