Verandas and decking

What you walk on is the cheap half of the decision. What holds it up decides how long it lasts. The substructure needs air under it and a way for water to leave, so joists sit clear of the ground on pads or posts, never buried in soil, and never sealed against the house wall where they would bridge the damp course. Posts go into galvanised shoes set in concrete, not into the concrete themselves, because a post cast into the ground is a post rotting from the middle out. Joist spacing follows the board, not habit: composite boards sag at spacings that softwood would take without complaint. Everything gets stainless or properly coated fixings, and within sight of the sea in Kerry or west Cork that is not a luxury, it is the only thing that stops rust streaks appearing down a new deck by the second winter. Then the board itself. Pressure treated softwood is the cheapest, takes a stain, and wants cleaning and recoating every couple of years. Hardwood is dense, dark and beautiful, expensive, and goes silver unless you oil it. Composite costs more up front, never gets painted, and does not splinter, which is what sells it to people with small children and dogs. None of them is slip proof in an Irish winter. Algae is what makes a deck slippery, not the material, so a shaded deck under trees will need washing whatever you spend. Give it a slight fall away from the house, leave gaps that actually drain, and keep the leaves off it. Last, think about the roof before the deck is built, not after. A veranda roof needs posts standing on the substructure, which means those posts have to be designed in from the start and the deck built around them.

Open deck, or covered veranda?

An open deck is used on maybe thirty good days a year here. A roofed veranda with a glass or solid roof, gutters and a light is used most of the year, and it keeps the rain off the back door and the kitchen window. It costs more, it needs its own drainage, and if it is large or high it can need planning permission, which we check at the survey. Most people who have had both say the roof is the part they would not give up.