Pouring a Driveway Against Your House in Melton: Weep Holes, Slab Edges and Joints

On most blocks in Melton, Cobblebank, Aintree and the newer estates out toward Rockbank, the driveway does not stop at the garage door. It wraps along the side of the house as a path, runs past the meter box and the bins, and often turns into a strip of concrete right around to the back. That strip is where a driveway is most likely to cause a problem for the house itself rather than just for the concrete.

The reason is simple. Everywhere else, the slab sits in open ground. Against the house, it meets brickwork, the edge of the house slab, weep holes, downpipes, the sewer and stormwater connections and the gas meter. Each of those has its own rules, and a driveway poured without thinking about them can quietly undo work your builder did to keep the house dry and stable.

Finished level is the first thing to get right

The most common mistake we see is concrete finished too high against the wall. It usually happens for innocent reasons. The garage slab is set high, the concretor matches the driveway to it, and the side path simply carries that level along the house. Or a new slab is poured straight over an old path or compacted topsoil, adding its own thickness on top.

The building regulations set minimum clearances between the finished ground or paving level outside and the floor level and damp proof course of the house, and those clearances differ depending on the situation. We will not quote a number here because it depends on how your home was built and which provisions apply, but the principle is consistent: paving should sit comfortably below the damp proof course and below the weep holes, and fall away from the wall. If you are unsure what your home needs, your builder's documentation or a building surveyor can confirm it, and we check it on site before we set any levels.

Do not cover the weep holes

In a brick veneer home, the small vertical gaps near the bottom of the brickwork are weep holes. They let any moisture that gets behind the bricks drain out and allow the cavity to breathe. Concrete poured up and over them, or so close that water splashes into them every time it rains, traps moisture in the wall cavity and can lead to damp problems inside.

They are easy to cover by accident, especially where the side path is being built up to meet a higher garage slab. If the only way to make the levels work is to bury the weep holes, the levels need rethinking, not the weep holes.

Leave the slab edge alone

On many homes the outside edge of the house slab is meant to stay visible. Depending on how the house was built, that exposed edge can form part of how the home is protected against termites, because it lets an inspector see any activity coming up the outside of the slab. Concrete poured hard against it, or over it, can compromise that. Check your builder's handover documents for how your home's termite protection works before anything is poured against the slab edge, and ask your concretor how they intend to finish the junction.

An isolation joint against the wall

Melton sits on reactive basalt clay that swells in wet winters and shrinks over long dry summers. The house and the driveway are on different footings, built to different standards, and they will not move together. When concrete is poured tight against the house with no separation, the two slabs are effectively locked. As the ground moves, the driveway can push on the brickwork or drag on the house slab edge, and cracks appear in places nobody expected.

The fix is an isolation joint, a compressible strip that runs the full depth of the new slab where it meets the house, so each can move on its own. It costs very little at the time of the pour and is very hard to add afterwards. We cover joints more generally in our article Why Melton Driveways Crack, and What Actually Prevents It.

Falls, downpipes and pits

A side path that falls toward the house delivers water straight to the footings, which on reactive clay is one of the main causes of footing movement. The side path needs to fall away from the wall and toward a drain or an open area that can take the water. Our guide Driveway Drainage in Melton: Where the Water Has to Go explains how falls, grated drains and the legal point of discharge fit together.

Downpipes need to stay connected to the stormwater system, not end up discharging onto the new concrete. Sewer inspection openings and stormwater pits must stay accessible at finished level, so they are raised or adjusted rather than concreted over. Plumbers and the water authority will need to get to them one day, and breaking out a section of new driveway to find a buried opening is an expensive way to discover it was covered.

Meter boxes and services

Gas meters, water meters and electrical pits along the side of the house need clear, level access, and some have clearance requirements of their own. Where a pour runs past them, we form around them properly rather than finishing the concrete up against the meter or burying a pit lid. It is also worth checking where the gas and water service lines run before excavating along the wall, because they are often shallower than people expect.

What we do before pouring

Before any concrete goes down beside a house, we check the floor level, damp proof course and weep holes against the planned finished level, confirm the falls, mark every downpipe, pit and meter, and allow for an isolation joint along the wall. Where the levels do not work, we say so at the quote stage and offer options, such as stepping the path down, adding a grated drain or setting the driveway lower at the garage door, rather than discovering the problem on the day.

If you are planning new Concrete Driveways or an Exposed Aggregate & Decorative Finishes job that runs along the side of your house anywhere in Melton, Kurunjang, Cobblebank, Rockbank or Diggers Rest, ask us for a site visit and we will set out the levels with the house in mind from the start.