After 11 years in facilities and estates procurement—having transitioned from the damp, noisy reality of working on the tools as a surfacing subbie to the arguably even noisier world of client-side contract management—I’ve developed a singular, obsessive focus. If you want to stop getting called out to site on a rainy Tuesday morning to explain why a pavement is crumbling or why someone’s heel has been caught in a poorly finished joint, you have to stop writing "fluffy" specifications.
I keep a personal, battered black notebook in my office. It’s my "Site Inspector’s Hit List." It contains every single thing I’ve been pulled up on during handover inspections over the last decade. The common denominator in every dispute? Vague language. Contractors who say "to BS standard" without naming the specific standard are my number one pet peeve. If you don’t define it, you haven’t specified it. Here is how you write a spec that survives the scrutiny of both the site inspector and the legal department.
1. The "What Fails First?" Philosophy
Before I ever write a word about the final finish—be it high-end resin or standard asphalt—I ask myself: What fails first?
Want to know something interesting? in almost every instance, it’s not the top layer. It’s the prep. If you don't compact your sub-base correctly, or if you skimp on drainage gradients, no amount of expensive surface material will save you. When specifying, you must dictate the preparation process as strictly as the installation. If a contractor tries to shave costs by skipping the sub-base density test or ignoring the moisture content of the substrate, your "10-year warranty" is effectively worthless the day they pack up their trucks. ...where was I going with this?
2. Specifying Measurable Standards (No More "Approximate" Dimensions)
I absolutely hate seeing "approximate" dimensions on drawings. If it’s on the drawing, it should be the target. If you don't define the tolerances, you lose the right to complain when the levels are out. To avoid the "standard" argument, you must cite the exact codes. Use these as your bedrock:
- BS EN 1436: Essential for road markings. If your car park markings disappear after six months, you need this standard in your tender pack to hold the contractor to the specific luminance and skid resistance values. BS 7976: This is for pendulum slip testing. If you are specifying pedestrian routes, you need to state that the contractor must provide a test report verifying the PTV (Pendulum Test Value) post-installation. TSRGD (Traffic Signs Regulations and General Directions): If you’re marking out a site, don’t guess. Reference the current TSRGD so your site doesn't end up looking like a DIY project. Part M (Building Regulations): The holy grail for accessible routes. If your gradients are too steep, you aren’t just looking at a dispute; you’re looking at a liability nightmare regarding disability access.
3. Material Trade-offs: Tarmacadam vs. Resin vs. Concrete
Every material has a breaking point. You need to choose based on usage, not just aesthetic. Pretty simple.. Use the table below to decide what fits your site requirements.
Material Primary Strength "What Fails First?" Best For Tarmacadam/Asphalt Flexibility & cost-efficiency Oxidation & surface cracking Large car parks & heavy traffic routes Resin Bound Aesthetic & permeability UV degradation & base movement Pedestrian footpaths & "feature" areas Concrete Extreme load-bearing Cracking at joints & spalling Loading bays & heavy HGV areas4. Prep Work and the Freeze-Thaw Cycle
In the UK, the weather is your silent, destructive partner. I always cross-reference my project timelines with data from the Met Office. If you are scheduling a pour or a lay in late autumn, you are inviting moisture into your sub-base. When that freezes, it expands. The freeze-thaw cycle is the primary cause of premature surface failure in England and Scotland. If your specification doesn't mention moisture mitigation or temperature windows for laying asphalt, don't https://gb.kompass.com/c/news/1/how-property-managers-are-specifying-access-routes-for-compliance/7a3bf450-4884-4dfd-8c6d-ba8f5d025f4f/ be surprised when your site looks like a cratered moon by March.
5. Documentation: The Handover Trap
Contractors love to say, "We’ll provide the test certs at handover." That is the red flag that keeps me up at night. If you wait until the end to see the compaction tests, the moisture reports, or the PTV scores, you have zero leverage to make them fix it. They’ve already been paid, and they’ve already demobilised.
Change your procurement policy today: Require all test requirements and certifications to be submitted at the tender stage as proof of competence. I often point colleagues toward Kompass to verify the background and certifications of potential suppliers before we even invite them to quote. If they don't have the paperwork to prove they can do the job before they start, they shouldn't be on your list.
6. Tools to Streamline Your Spec
Writing a spec is only half the battle; ensuring the materials are consistent is the other. I frequently use Ready Set Supplied to ensure that the products I’m specifying are actually available and up to current manufacturing standards. When I am writing the Bill of Quantities, I need to know that the materials aren't just "theoretically" available but are ready for supply chains to handle. This prevents the "we couldn't get that product so we used this cheaper alternative" excuse, which is the fastest route to a long-term maintenance failure.
Final Checklist for Your Tender Pack
To reduce your liability and prevent disputes, ensure your tender pack explicitly covers the following:
Named Standards: Do not just say "BS." Write "In accordance with BS EN 1436:2018." Clear Warranty Terms: Define what is covered under the warranty (e.g., structural failure) and what is excluded (e.g., normal wear and tear). Test Requirements: List specific tests (compaction, slip resistance, material density) that must be submitted at the tender stage, not at handover. Detailed Prep Schedules: Don't leave the "how" to the subbie. Detail the required sub-base thickness, the specific membrane types, and the required drainage falls. Material Specifications: Define the asphalt/tarmacadam grade or resin binder specifications explicitly. If you don't name the grade, you will get the cheapest grade possible.Ultimately, a good specification is a shield. It protects you from the contractor who wants to do the bare minimum, it protects your budget from expensive rework, and most importantly, it protects your site from becoming an endless cycle of patching and pothole filling. Stop hoping for quality and start mandating it.
