Concrete yards are ordinary in this town. Houses were sold with a hard standing at the back, or a later owner poured one. This is how we decide whether a deck can live on top.
When the concrete can stay
We want three things. The concrete should be stable underfoot, without a rock or a hollow. It should not be breaking into pieces. And it should have a fall that sends rain away from the house, or a fall we can still work with.
If those are true, the yard can stay. We set the frame on supports that suit that surface, and we keep the timber out of any puddle line. A deck is not glue. We do not stick boards straight to damp concrete and hope the moisture stays down.
A crack that has stepped, one side higher than the other, is a warning. We mark it on the visit. Door height matters. Many concrete yards were poured high, close to the sill. Add a frame and a board and you may block the door. We measure that gap first. If there is no room, the concrete cannot simply be covered. Something has to give, and we say what.
Levels, doors and a fall for rain
Rain on concrete moves fast. The deck has to respect the path it already takes, or give it a better one. We do not create a dam at the wall. A small gap at the house edge lets water out instead of into the brickwork.
Air bricks stay open. The damp-proof course stays above the finished boards. Those two checks protect the house, not just the deck. A yard that was already too high makes both checks tighter. We would rather tell you on day one.
The planning reading is easy to get wrong here. Old concrete has a thickness. People measure from the top of the yard and think the new boards are only a joist higher. We measure the finished walking surface against the surrounding ground. If that reading is more than thirty centimetres, the ordinary householder route is probably over, even though the yard felt low. We write the reading down. We do not treat the concrete as a free extra that the ruler ignores.
Steps down to the remaining garden need a landing, not a stumble off the last board. If the concrete ends in a lip, we deal with the lip. Covering it and leaving a trip is not a finish.
A frame that is not stuck to a failing yard
Where the concrete is sound, supports can bear on it if the load is spread and the support cannot punch a hole. Where it is failing, we do not ask it to carry the deck. Posts go beside it, into ground that can bear, or the broken area comes out so we can found properly.
The quote says if the concrete is coming out. Leaving a rocking yard under a new frame is how the boards start to bounce. The river and the flood plain still matter if your yard is on low ground. A deck over concrete should not become a sealed lid. Edges stay open. The flood water guide is the longer version. A hard yard in a dry street gets the same open edge, because rain is enough of a reason.
Composite boards are the usual request over an old yard. They cope with a damp void better than bare timber. Timber is still possible if you want it and the ventilation is real. Both need joists that are not lying on the concrete in a film of water.
Edges, steps and a quote
Guarding follows the drop, not the fact that concrete is underneath. A low yard may need only a neat step. A yard that ends over a fall needs a rail. Guarding and steps explain that split. Lights at the step are worth it if the concrete lip is staying. See deck lighting.
A quote lists what stays, what comes out, the frame and the boards. It includes the door clearance and the height reading. Ask for a quote and say "concrete yard" so we bring the right eye. We do not need a novel. We do need to stand on it.
Questions we get asked about old concrete
Do you always leave the concrete in place?
No. We leave it when it is stable and the door still has room. We take it out, or we found beside it, when it rocks, holds water, or sits too high. The visit is the decision. The quote repeats it in writing.
How do you measure height if the yard is already raised?
Against the surrounding ground, up to the new walking surface. The top of the concrete is not a free starting point. More than thirty centimetres of clearance and we talk about an application. A thick yard can cross that line with a slim frame.
Will rain get trapped under the boards?
Not if we keep the fall and leave the edges open. We do not seal the deck to the concrete like a lid. A gap at the house lets water away from the wall. Air bricks stay clear.
Can the deck stop part way across the yard?
Yes. We can cover the hard area and stop, or continue onto posts in the garden. The edge needs a proper finish and a safe step. We draw that line on the visit so the quote matches the part you actually want to walk on.