Kieran McCarthy: Picking the perfect patio

Unfortunately, it’s approaching end-of-life now and is looking the worse for wear. We are planning to replace it, but we are not sure what the best option is. I assume with the climate getting wetter and wetter, decking is no longer a runner? 

We’d prefer something low maintenance at any rate. Is composite decking the way to go? Would paving be more practical or would that create drainage problems? Or what about outdoor tiling? (First World problems, I know!). 

I’d appreciate any advice you might have.

Yours in hoped-for outdoor bliss, Bruce Cook.

Hello Bruce, 

Thank you for this seasonal question. As I write this article I look out the window to yet another heavy shower in what must be the wettest autumn (and now winter) in my memory, and no doubt our attention will be drawn to this fact in the evening news weather forecast in the coming days. I guess timber decking (and indeed wall cladding) was envisioned in sunnier times when both our Celtic Tiger economy and our summer evenings were forecast to go on forever. 

I’m sure as you look at your decking which is now grey and black, like the sky, you need to future-proof your patio in a climate that seems to be edging towards the Monsoon.

So, what are the options?

In my view, there are two main options; more (composite) decking or new paving (which may be paving slabs or tiles) so let’s look at these in turn.

In truth, the decking you have fitted suffers from the fact that your decking boards, though pressure treated, are exposed broadside-up, to the full extremes of the Irish North Atlantic climate. Every drop of rain local to this area will inevitably land and remain on your decking (as there are no falls/drainage).

These timber decking boards are therefore a ticking time bomb whose life expectancy is about 8-12 years depending on your exposure (believe me I know, having replaced the decking in our house and mobile home some time ago). So, can they still be used? Yes, if you’re careful.

There are modern equivalents that offer much more durability and indeed longevity. We recently built a raised deck outside our office and we used a composite (plastic) deck on the surface in lieu of a timber deck. The composite deck will certainly outlast the timber structure underneath which forms the structure of the deck, so this now becomes the leading edge in terms of longevity.

When I was repairing our mobile home deck I did find that the timbers underneath were in much better condition than the timber under our house deck. The reason for this was that, due to their elevated height (the deck was raised about four feet above the ground) we had great ventilation (air flow) underneath to dry the structural timbers when they became wet.

This really was key and indeed I have always found that decking really only offers true value when installed in a garden with tricky levels as it is a very cost effective way to deal with this issue when constructed and detailed correctly.

Paved patios are very different both in terms of construction and lifespan. Paved areas require a compacted hardcore foundation followed by a paved or tiled surface which falls slightly to a drainage gully which conveys the rainwater to a soakaway drain in your garden.

When it comes to the surface of the patio, you have a wide choice of materials to choose from which really depends on your budget and preference in terms of finish. The most cost effective option is probably a brick paving, where the paving bricks are set in grit and pointed in sand dust, whereas the most expensive hard paved patio is either a natural stone (eg polished limestone) or a ceramic tile.

These finishes are set in sand cement and their pointing material is dependent on what exact finish you chose.

There is little doubt that when compared to decking, hard surface paving is more forgiving and indeed more aligned to the Irish climate, but it does bring some drawbacks too.

If your house is mid terrace you will need to bring the hardcore in though your house in wheelbarrows, and in winter you will need to make sure that all your gullies are kept free from leaves and other airborne debris because if they block, your patio may hold water and indeed, if built at the level of your house, may cause water to be blown under patio doors. 

So, which one to use? 

For me it is down to the access available for bringing materials to your garden, the level difference between your finished patio height above your garden and, as is always the case, your budget.

• Kieran McCarthy is a building engineer and director of KMC Homes bespoke A-rated new home builder, serving Cork and Limerick. He is also a co-presenter of the RTÉ property show Cheap Irish Homes.

• Follow Kieran on instagram @kierankmc for more home-building information, tips and Q&A advice.

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