Keeping a garden room sound for decades, not seasons

What wears, and how fast

Different parts of the building age at very different rates, which is why a single lifespan figure is misleading.

The annual half hour

Once a year, ideally in autumn before the leaves land, walk round with a ladder and a torch.

• Clear the roof of leaves and check outlets and gutters run freely
• Look for ponding water on flat roofs after rain, which points to a fall problem
• Check the membrane upstands and any junctions for lifting or splitting
• Look at the cladding near the ground for splashback damage and clear soil away from the base
• Open and close doors and windows, check seals and adjust hinges
• Inside, check corners and reveals for any sign of damp or mould

Cladding: treat it or let it go grey

Untreated cedar and larch silver over time, which many owners like and which does not harm the timber. Treated cladding keeps its colour but needs recoating on a cycle that depends on the product and the exposure.

Decide which you want at the start, because switching from weathered timber to a coated finish means cleaning back a surface that has been ageing for years.

Ventilation is maintenance too

A garden room that stands closed up for weeks, particularly one with a shower or a gym in it, gets stale and damp. Leaving a trickle vent open, or running the extract periodically, prevents most humidity problems without any cost.

If you find condensation appearing regularly, treat it as a symptom rather than a nuisance. It usually means a gap in the insulation or vapour control, and it is far cheaper to investigate than to replace damaged timber.

Repairs we get called to

The common ones are blocked roof outlets leading to ponding and eventual leaks, splashback rot at the bottom of cladding where a path or bed was built up against it, and internal finishes damaged by condensation in buildings that were never ventilated.

All three are cheap to prevent and expensive to leave. Because we also carry out water damage repairs, plastering and decorating, we tend to see the internal consequences long before the owner realises where the water came from.