TubeAcademy
Module 04

Roof Structure

Intermediate 3-5 days The weathertight milestone

Getting the roof on is the biggest milestone — once you're weathertight, everything else can happen at your own pace. A simple gable roof is the most forgiving design for a first build. Steeper pitch = better for shedding rain and snow.

Featured video

Complete roof build from ridge to shingles. Clear explanation of cuts and angles.

Pro tips
·

A 30-40° pitch is ideal for the UK climate — steep enough to shed rain, shallow enough to be manageable to build.

·

Build a ridge beam supported on gable end walls, then hang rafters off it. Simpler than a full truss system for small cabins.

·

Temporary scaffolding or a good ladder system is essential. Don't rush the roof — falls from height are the #1 DIY building injury.

·

Get the roof membrane (breathable underlay) on ASAP, even before final roofing. It's your weathertight insurance.

Step by step
01

Choose roof style: gable (simplest), shed (mono-pitch), or gambrel. Gable recommended for first build

02

Calculate rafter length and birdsmouth cut angles (or use an online rafter calculator)

03

Install the ridge beam at the apex, supported by temporary posts or gable walls

04

Cut rafters with birdsmouth notches to sit on the wall plates

05

Install rafters in pairs, working from both ends toward the middle

06

Nail or screw rafters to ridge beam and wall plates. Add collar ties for rigidity

07

Install fascia boards at the rafter ends

08

Lay roof decking (OSB or plywood sheathing) across the rafters

09

Roll out breathable roofing membrane (e.g. Tyvek), staple in place, lapping uphill

10

Install battens for your chosen finish: tiles, metal roofing, or shingles

11

Metal roofing sheets are fastest and most DIY-friendly for a cabin

What you'll need
TOOLS
Circular saw (for rafter cuts)Amazon →
Speed square (for angle marking)Amazon →
Scaffold tower or good ladder systemAmazon →
Roofing nailer or hammerAmazon →
MATERIALS
Structural timber for rafters (47x150mm typical)Amazon →
Ridge beam (double thickness or engineered)Amazon →
OSB or plywood roof decking (11-18mm)Amazon →
Breathable roofing membrane (Tyvek or equivalent)Amazon →
Roofing battens (25x50mm treated)Amazon →
Metal roofing sheets or shinglesAmazon →
Ridge capping and flashingAmazon →

Amazon UK links carry our affiliate tag — no change to the price you pay.