Interlock Driveway Installation · Cambridge
Interlock Driveway Installation in Cambridge
A paver driveway is a structure you drive on. The pavers are the wearing surface; the base is the driveway, and the base is where the money and the care go.
A new interlock driveway in Cambridge starts with what is being removed and what is underneath it. Asphalt comes out, and then the question is how far down to go. The CMHA/ICPI construction standard sets a minimum compacted base of 150 mm (6 in) for a residential driveway on well-drained soil, and says plainly that wet or weak soils and colder climates need more. On a lot where the excavation reveals clay or silt a few centimetres under the old asphalt, which is common in the Preston and Hespeler subdivisions and far from rare elsewhere, the base goes deeper and a geotextile goes between the subsoil and the stone so the two do not mix over time.
What the quote specifies
- Excavation depth and base depth, in millimetres, so it can be checked on the day.
- Base material and compaction. Granular base compacted in lifts of 100 to 150 mm to 98 per cent Proctor, which is what the standard calls for and what a plate compactor can actually achieve. A base dumped in one lift and run over twice is not compacted, however it looks.
- Drainage. Where the surface water goes, and where the water that gets through the joints goes. On clay the standard recommends perforated drain pipe under vehicle areas; on a driveway that falls toward the garage, a trench drain at the apron is the difference between a dry garage and a wet one.
- Bedding sand screeded to a nominal 25 mm (1 in), uncompacted, never used to make up for an uneven base.
- Edge restraint along every unconfined edge. Without it the pavers walk outward, the joints open and the whole field loosens within a few seasons.
- Pavers, pattern and joint sand. Paver thickness suited to vehicles, a laying pattern that locks under turning tires, and polymeric sand swept and activated on a dry day.
Width, the apron and the City
If the new driveway is the same width as the old one at the street, the project is on your property and the City's involvement is limited. If it is wider, or the apron changes, Cambridge requires an Access Permit with a drawing before the work, and the City's stated maximum driveway width is 7 metres with a minimum of 45 per cent landscaped space kept on the lot. The City boulevard between the sidewalk and the curb is not yours to alter without Transportation Division approval. All of that is checked against your address during the site visit, and if the driveway fronts a Regional road the Region's Corridor Planning team is contacted as well.
How long it takes
Once permits and locates are in hand, a two-car driveway is usually three to five working days on site. The old surface comes out and the excavation is done on day one; the base is placed and compacted in lifts over the next day or two; screeding, laying, cutting, compaction and sanding take the rest. You can walk on it that evening and drive on it once the polymeric sand has set, which depends on the weather. What affects the quote most is the removal, the depth of base the ground demands, the drainage it needs, and how much cutting the shape requires.
Frequently asked questions
Can interlock go over my existing asphalt?
No, and anyone offering to do it is building a short-lived surface. The asphalt has to come out so the base can be built to depth and compacted. Laying pavers on an old slab or asphalt traps water, prevents drainage and guarantees heaving at the first winter.
Do I have to use the same width as my old driveway?
Not necessarily, but any change in width at the street or to the apron needs the City of Cambridge's Access Permit, and the City caps driveway width at 7 metres with 45 per cent of the lot kept as landscaped space. We check what the rules allow at your address before drawing anything.
Will the new driveway heave like the old one did?
Not if the base is built to depth for the ground that is actually there, compacted properly, separated from clay with fabric and drained. Heave needs fine soil, water and frost together; a proper base removes two of the three. That is the whole reason the quote specifies the base rather than just the pavers.
Serving Cambridge and surrounding areas. Contact us for a no-obligation quote specific to your property.