Technical Installation · 6 min read

How to Assemble a Flat Pack Shed: Panel-by-Panel Guide

Putting up a flat-pack timber shed, step by step: what's in the box, the tools you need, the order the panels go together and the mistakes to avoid.

Assembly guide

Build your shed panel by panel

Two people, a level base and a cordless drill. Here's the order everything goes together, and the small things that make the difference.

Every NextdaySheds building arrives as numbered panels with pre-hung doors, every fixing and a printed guide. Nothing needs cutting except the roofing felt. Most sizes up to 8 × 6 take two people half a day; larger buildings take about a day.

Read the printed guide for your model before you start — it has the panel layout for your exact size, door and window configuration. This page explains the general order and the tips that help.

Before you start

✓A firm, level base that is at least the building's external size — check it with a spirit level in both directions
✓Two people: wall and roof panels are awkward for one person to hold
✓A dry, still day. Roof boards and felt are much harder to fit in the wind
✓Unpack and lay the panels out by number so you can find each one quickly
✓Count the fixings against the list in the guide before you begin

Tools you'll need

Essential

Cordless drill/driver with screwdriver bits
Hammer
Step ladder
Spirit level
Tape measure
Craft knife for the roofing felt

Useful

A second drill so two people can work at once
Gloves
A soft mallet for nudging panels into line
Clamps to hold panels while you fix them

The order it goes together

1. Floor

Place the floor on the base with the bearers running front to back (or as the guide shows). Check it is level and square by measuring both diagonals — they should match.

2. Back and side walls

Stand the back panel on the floor, then a side panel, and screw them together at the corner. Add the other side. Don't fully tighten everything yet; leave a little play until all the walls are up.

3. Front wall and doors

Fit the front panel with the pre-hung doors. Check the doors open and close freely before you fix the walls to the floor — a door that binds usually means the floor or walls are slightly out of square.

4. Fix the walls down

With everything square, screw the bottom of each wall panel into the floor bearers, then tighten all the corner fixings.

5. Roof

Fit the roof support (the ridge purlins on an apex, the rafters on a pent), then lay the tongue-and-groove roof boards and fix them down.

6. Felt or EPDM

Roll out the felt with plenty of overlap, starting at the lowest edge so each layer sheds water over the one below. Fix with clout nails along the edges and finish with the fascia boards. If you chose the EPDM rubber roof, follow its separate instructions for the adhesive.