Advanced options
Alcoves are NEVER square: measure the width at every shelf height (front and back), cut each shelf to its own line, and scribe to the wall for the gap-free look. 18mm board minimum for books (MDF paints beautifully; pine or oak-veneered ply for a stained finish): over ~80cm spans, books will bow 18mm MDF: go 25mm or add a front lipping. Battens on 2 sides + back, screwed into plugs (or studs), shelf screwed down through the top.
What The Alcove Shelving Calculator Works Out
- Shelf board needed: alcove width x number of shelves, in linear metres, divided into 2.4m boards at your depth. A 90cm alcove with four shelves is 3.6m of board, two lengths.
- Support battens: two sides plus the back for every shelf (2 x depth + width), in metres of 25 x 50mm softwood. Screw and plug them to the wall at each level, then screw the shelf down through the top.
- Fixings: about six screws and plugs per shelf for the battens plus screws down through each shelf, and the square metres of surface (both faces) to paint or finish.
- Board thickness and source (advanced): 18mm is the painted-finish workhorse, 25mm for heavy loads and wide spans, 38mm for the scaffold-board look. Buying 2440 x 1220mm sheets and cutting strips is often cheaper than ready-cut boards: the card works out shelves per sheet from your depth and width.
- Battens to buy (advanced): packs the side pieces (depth less 3cm so they hide behind the front edge) and back pieces into 2.4m lengths, plus the front lipping if chosen. The lipping stiffens the shelf like a beam flange and hides the MDF edge.
- Load and span check (advanced): the weight each shelf will carry (books about 25kg per metre, vinyl 40kg, ornaments 8kg) and whether your span is within the limit for the board: about 80cm for 18mm MDF under books, rising with thickness squared and by half again with a lipping. Over the limit it tells you the fix.
- Materials cost (advanced): boards or sheets plus battens at your prices, with a cost per shelf. 18mm MDF is about GBP 35 to GBP 50 a sheet or GBP 12 to GBP 20 a 2.4m board; 25 x 50 batten GBP 3 to GBP 5 a length. Fitted-furniture joiners quote hundreds per alcove for the same volume.
- Paint (advanced): litres for both faces, edges and lipping at your number of coats and about 12m2 per litre. Seal MDF edges with primer or diluted PVA first; two top coats in the room's woodwork colour make the shelves read as architecture rather than furniture.
- Number of alcoves (advanced): multiplies everything for the matching pair either side of a chimney breast.
- Cutting list (advanced): every piece with its size, quantity and notes. Alcoves are never square: measure each shelf at its own height, front and back, cut to its own line and scribe to the wall. A metre of hardbacks runs 25-plus kilos, so battens go into plugs in masonry or into studs, never plasterboard alone.