Built-in shelving and bookshelf design in Nairobi

Shelving looks like the simplest thing on this site and it is the one most often built wrong, for a single reason: almost nobody calculates the span. A shelf that looks perfect empty and bows visibly under books is the most common piece of failed joinery in Nairobi houses.

Span is the whole engineering problem

Every shelf is a beam, and a beam’s stiffness falls off sharply with length. Double the span and you do not double the sag, you multiply it several times over.

So the useful questions are what goes on it and how far apart the supports are. Books are among the heaviest things people shelve, at roughly 25 to 30 kilos per running metre packed. A 19mm MDF shelf carrying that over 900mm will bow within a year. The same load over 600mm, or the same span in 25mm marine ply, or an 19mm shelf with a hardwood lipping glued to the front edge, will not.

That lipping trick is worth knowing: a 20mm hardwood strip on the front edge stiffens a shelf far more than its size suggests, because it is at the point of maximum bending. It also gives you a clean edge to finish.

If you tell us it is for books we specify for books. If it is for ornaments we can go longer and thinner, which looks better.

Floating, alcove, or a full wall

Floating shelves carry their load on a concealed bracket or a batten housed into the wall, so there is nothing visible underneath. They look light, and their span limit is stricter than anything else because there is no support at the front. In a Nairobi block wall they are straightforward; in a partition wall they need the fixing points planned against the studs.

Alcove shelving is the best value in the house. A chimney breast or a structural recess is otherwise dead space, and shelves scribed to the alcove look built-in because they are. Every alcove is a slightly different width top to bottom, so each shelf is cut individually rather than five identical ones forced in.

A library wall is a different project: floor to ceiling, usually with a ladder or a run of lower cupboards, and it becomes the room rather than sitting in it. This is high-value bespoke work and we could not find a reliable Kenyan published rate for it, so it is quoted from a drawing rather than listed here.

Under-stairs storage deserves a mention because it is the most wasted space in most maisonettes, and the shape makes it fiddly enough that developers leave it as a cupboard with a door. Fitted properly with graduated drawers and pull-outs it is genuinely useful.

Adjustable or fixed

Fixed shelves at planned heights look better, because the spacing can be proportioned to the room and there are no visible tracks or holes.

Adjustable shelves are more useful, and an adjustable shelf that has never been adjusted has cost you the appearance for nothing. Our honest advice is fixed for display and for a library where the book heights are known, adjustable in a store cupboard or a child’s room where the contents will change.

Timber and finish

Carcass and shelves in marine ply or blockboard where the span is working, MDF where it is painted and the span is short. Exposed edges lipped in hardwood, which is both stiffer and the only way a painted shelf edge looks crisp rather than soft.

In a room with a wet season and a dry one, a long shelf will move. Fixing it so it can move a fraction without splitting, rather than screwing it rigid at both ends, is why some shelving creaks and cracks its paint and some does not.