Why this site exists
Most roofing content is a sales page
Written to book a job, not to answer the question. We write the answer first and let you decide what to do with it.
Every page is dated and sourced
Facts come from manufacturer documentation, published standards and government agencies, and we say when a page was last checked.
Nothing here is sponsored
No manufacturer, system or contractor pays to appear on this site, and no page is written to sell a particular product. Where we think an option is wrong for you, we say so.
About this reference
Written for the person who signs the invoice
A commercial roof is bought once or twice in a career, usually under pressure, usually from a bid that is hard to compare with the one next to it. The gap is not intelligence. It is vocabulary.
These guides give you the vocabulary. What a cover board does, why an overlay voids a warranty, what a square actually costs, which line items a cheap bid quietly leaves out.
Nothing here is written to sell you a roof. The transactional pages are marked as such and live in their own section, so the guides stay guides.
Read our methodologyThe six pillars
Where to start
Roof systems
TPO, EPDM, PVC, modified bitumen, built up and metal. How each one works and where it fits.
Read the guide02Flat roofs
Materials, drainage, slope and why low slope roofs fail differently to steep ones.
Read the guide03Roof assembly
Deck, insulation, cover board, vapour control and the flashings that decide whether it leaks.
Read the guide04Replacement
Tear off versus overlay, sequencing an occupied building, and what a real timeline looks like.
Read the guide05Cost
What drives the number, what a square costs, and how to read a bid that looks too cheap.
Read the guide06Contractors
How to choose one, what to ask, the red flags, and the clauses that matter in the contract.
Read the guideMost read
The three guides owners open first, and the ones we update most often.
Get the bid comparison sheet
One page. Every line item a commercial roofing bid should contain, so you can lay three of them side by side and see what is missing.
Open the sheet- Tear off and disposal
- Deck repair allowance
- Insulation type and R value
- Cover board
- Flashing and penetration detail
- Warranty term and who backs it