How to Supervise a Renovation When You Know Nothing About Construction

You have hired a crew, but you do not know how to lay tiles or pour a floor screed properly. How can you check that they are not doing sloppy work? Here are simple rules for a customer with no technical background.

The main principle: trust but verify

A good site manager does not mind being checked. A bad one will say “leave us alone, you don’t understand anything anyway”. That is the first indicator: if the foreman forbids you from visiting the site or asks you not to ask questions – run.

Your job is not to do the work for them, but to make sure they are doing it correctly. You do not need to know how to hold a trowel. You just need to know a few simple checkpoints.

How to check the floor screed

The screed is the foundation of your floor. If it is uneven or weak, the laminate or tiles will crack and move.

What to check:

Levelness. Take a long level (at least 1.5 meters) or a straight batten. Place it on the floor in different places. The gap between the batten and the floor should not exceed 3–4 mm per 2 meters.
No cracks. Walk across the screed. If you hear a hollow sound or see a web of cracks – something is wrong (wrong mix, dried too fast).
Drying time. Cement screed takes at least 2–3 weeks to dry. If the crew says “we can lay the laminate tomorrow” after one week – they are wrong or lying. The moisture content of the screed should be below 2–3% (there are special meters, but you can also do a simple test: put a plastic sheet taped down overnight. If there is condensation under the sheet in the morning – it is too early).

How to check plastered walls

Crooked walls mean gaps behind wardrobes, skirting boards that do not sit flush, and shelves that keep falling.

What to check:

Verticality. Put a level against the wall in several places. The deviation should not exceed 2–3 mm per meter.
Flatness. Put a long straightedge or a batten against the wall vertically, horizontally, and diagonally. The gap should not exceed 2–3 mm.
90‑degree corners. Put a square against inside and outside corners. They must be exactly right. If a corner is “leaning”, you will not be able to place a wardrobe against the wall – it will stand on only one leg.

A simple trick: if the wall looks flat by eye, take a bright flashlight and shine it along the wall. Shadows from small bumps will appear immediately.

How to check tiles

Tiles are the most visible part of a renovation. Crooked tiles are obvious to everyone, but it is better to check before the adhesive dries.

What to check:

Flush surface. Run your hand across the tile joints. There should be no “steps” – one tile higher than another.
Grout joints. The grout line thickness should be the same everywhere (typically 2–3 mm). That is what the spacers are for.
Hollow spots. Tap each tile with a wooden handle. The sound should be the same everywhere – a hollow sound means there is a void under the tile. Sooner or later such a tile will fall off.
Cut corners. At corners, the tile should be cut at 45 degrees or covered with a plastic corner. Dirty chipped edges and protruding raw edges are bad.

How to check the electrical system

You cannot see the electrical system, but mistakes here are dangerous for life.

What to check:

Matches the plan. You should have a plan showing where each socket and switch is located. Check that they are all in place. Did they forget the socket by the bed?
Wire colors. In modern wiring, phase is brown or black, neutral is blue, ground is yellow‑green. Make sure the colors are consistent in the panel and in the sockets. Color chaos is a sign of sloppy work.
Terminal tightness. In each socket and switch, the wires must be firmly clamped. If a wire is loose, it will heat up and spark.
Grounding. All sockets (except double‑insulated ones) should have grounding. Check with a special tester (available at any hardware store) or hire an outside electrician for a diagnostic.

How to check soundproofing

You can easily check soundproofing before the final finishes. Go one floor above and ask your neighbor to walk around or drop some keys. If you hear it – the insulation is poor. If you only hear muffled sounds – it is fine.

Also check whether sound travels through the walls: knock on your wall while putting your ear to the neighboring wall (or ask a helper).

Photo documentation of hidden work

The most reliable way to control what you cannot see – take photos before it is covered up.

Before you close the walls with drywall or pour the screed, photograph:

How the pipes run (so you know where to drill in five years).
How the electrical wires run (so you do not accidentally drill into them when hanging a shelf).
Where the joints and connections are (the weakest points).

Save these photos. They will be useful years later.

When to hire an independent inspector

If you feel the crew is doing something wrong but cannot prove it – hire independent technical supervision. They come to the site, check everything against standards, and issue a report.

Summary: what you need to supervise

To supervise effectively, you need three things:

A level (laser is best, but a 60–80 cm bubble level works too).
A flashlight (bright enough to see wall imperfections).
A contract with clear quality criteria.

And most importantly: do not be shy to check. You are paying for it. You have the right to know what you are paying for.