Gazebo and pergola design in Nairobi

gazebo is searched 2,900 times a month in Kenya, which makes it the single most-searched thing on this entire site, roofing included. pergola adds another 1,600. Almost all of that search is people looking at designs rather than pricing a job, which is why this page leads with what the structures are rather than with a rate card.

Worth knowing who currently sells these: the market is largely held by shade-sail and tent fabricators working in steel and fabric, not by woodworkers. A timber structure is a different object with a different lifespan.

Gazebo, pergola or neither

A gazebo is a roofed structure, usually freestanding, that you can sit under in rain. It needs a real roof, which means it needs a real frame, and in Nairobi it wants gutters if it is anywhere near a path.

A pergola is an open frame, usually attached to the house, that filters sun rather than stopping rain. The rafters are spaced to throw shade at the hour you actually use the space, which is a design decision most pergolas get wrong by defaulting to even spacing.

A carport is a pergola that has to carry a real roof load and stand up to a reversing car, so the posts and their footings are a different specification entirely.

Deciding which you want by what it will be used for, rather than by the word, saves the commonest disappointment here: a pergola bought by somebody who wanted to sit outside in the rain.

Timber choice is the whole job outdoors

Indoors, timber species is largely about appearance. Outdoors it decides how long the thing lasts, and the right answer depends on position rather than budget.

A structure in an open compound takes direct sun and dries hard between rains. One under mature trees, which describes most of Karen and the valley side of Kitisuru, sits in damp shade and never fully dries. Those are opposite problems. Sun degrades the finish and opens joints; persistent damp in shade invites rot and insects at the ground contact and in any joint that holds water.

So the specification changes: denser hardwood and a finish schedule for the exposed position, and ruthless attention to ground contact, end-grain sealing and water-shedding joint detail for the shaded one. A structure built to the wrong one of those fails early and it is never obvious why.

Ground contact is where it fails

Almost every failed timber structure we are asked to look at has failed at the bottom of a post. Timber in direct contact with concrete or soil wicks water upwards, and the rot starts inside where nobody sees it until a post moves.

Posts should sit on a raised metal shoe or above a concrete upstand, clear of standing water, with the end grain sealed. It is a small detail at build time and it is the difference between eight years and twenty-five.

Decking

Timber decking is priced per square metre and the honest position is that we could not find a reliable published Kenyan rate for all-timber decking, so it is quoted rather than listed. What we can say is that decking has the worst margin of any outdoor work we do and the highest maintenance expectation, and anyone telling you a timber deck in Nairobi needs no attention is selling rather than advising.

Season it right

Outdoor work stops in the rains. Long rains run March to May and short rains October to December, and a structure built in the wet cannot be finished properly because the timber never dries enough to take a coating. June to September is the window, which means a gazebo you want for December is designed in August.