Cracks, condensation and drying out: your first year

Are settlement cracks in a new build normal?

Yes, small ones are. A new home goes through a settling-in period, usually over the first 12 months. Minor cracks in walls or ceilings, and doors or windows that feel slightly tighter or looser, are normal then and don't usually mean poor workmanship. NHBC says most homes crack at some point, however well they are built, and the cracks are rarely serious.

NHBC's building standards expect it too. Cracks up to 2mm wide may appear where walls meet floors and ceilings, from shrinkage and movement. Where the stairs meet a wall, a crack up to 4mm may appear.

Shrinkage, settlement or something structural?

Three of the causes NHBC describes are:

• Shrinkage cracks appear as plaster, mortar and concrete dry out. They are usually straight, often near the ceiling or floor, and an even width under 2mm.
• Thermal movement cracks appear where different materials meet, such as an outside wall and an inside plasterboard wall, or at the joints in a plasterboard ceiling. They open and close with the seasons.
• Settlement cracks appear as the house beds down on its new foundations. They can run in any direction. Under 2mm, they are unlikely to affect the structure.

The warning signs are different. Cracks from ground movement, such as subsidence, tend to be wide at one end and narrow at the other.

When should I report a crack?

NHBC says to contact it if a crack:

• is wider than 5mm at any point;
• is wide at one end and narrow at the other;
• is straight and stays wider than 2mm;
• is diagonal or stepped, at any width;
• shows both inside and outside;
• runs along the damp proof course (the waterproof layer near the bottom of the outside wall) and the brickwork at the corners just above or below it is uneven, or extends below the damp proof course;
• comes with doors or windows that start to stick or swing open;
• has got noticeably wider or longer since you first saw it.

In the first two years, tell your builder first. If you make a claim with NHBC, it says to tell your buildings insurer at the same time, in case the cause turns out to be something NHBC doesn't cover.

A trick we used a pencil mark at each end of a crack, with the date beside it. A few weeks later it was obvious whether it had grown.

Who fixes cracks in years one and two?

In the first two years, report cracks to the builder. The builder must fix anything that breaks the warranty standards. Shrinkage on its own isn't covered unless the builder failed to meet NHBC's standards. In practice, the NHQB says most developers will repair shrinkage cracks and nail pops if they are excessive. A nail pop is a small raised spot where a screw or nail under the plaster shows through.

You can also fill small cracks yourself. NHBC says a crack of 2mm or less can be repaired with filler, grout or sealant, and may come back after a year or so from seasonal movement. Take a dated photo first.

After year two, NHBC's cover is for structural damage only. Cracks that don't affect the structure or keep the weather out aren't covered from year three. That is a good reason to report a crack you are unsure about inside the first two years.

How long does a new build take to dry out?

NHBC says about nine months to a year, depending on how the house was built and the weather when you move in. The NHQB says around 12 months, depending on the size of the house.

To help it dry out evenly:

• keep the temperature steady, and turn the heating up gradually, especially in winter;
• keep trickle vents open (the thin slots in the window frames);
• always use the kitchen and bathroom extractor fans;
• don't dry clothes on radiators;
• keep big furniture a little away from the walls.

NHBC adds that heating the house fast makes shrinkage worse, so don't put the heating on full if you move in during winter.

You may also see a white powder on outside brickwork. It is called efflorescence: natural salts coming out as the wall dries. It often fades on its own. If white deposits keep coming back on an inside wall, it could mean a leak, and you should get it looked at.

Is condensation normal in a new build?

Some is. A new house holds a lot of water from building, and it is designed to be airtight. Condensation forms when warm, damp air meets a cold window or wall. It should ease as the house dries out.

You may also see moisture under the roof felt in the loft in cold weather. NHBC says this usually clears, because the roof space is ventilated. Keeping the loft hatch closed helps.

To keep it down, use the extractor fans, cover pans, keep the kitchen and bathroom doors shut while they are steamy, and wipe condensation away when it appears.

Contact the builder if condensation is persistent or heavy, or you see damp patches or mould. It can point to a problem with insulation or ventilation.

Why are my doors and windows sticking?

Usually because the timber and frames are moving as the house dries. The NHQB says doors and windows can feel stiff at first, especially south-facing ones in the sun, and should get easier with use. Don't force them. NHBC says seasonal movement can make doors stick in their frames or swing open.

It is different when a door starts sticking at the same time as a new crack appears nearby. NHBC lists that combination as a reason to contact it.

Is creaking and clicking normal?

Mostly, yes. Creaks, pops and clicks are common as timber and pipes expand and contract, especially when the heating comes on. If the noise is constant, very loud, or comes with another problem, ask the builder to look. Creaking stairs and floors are covered on the hall and stairs page.

What isn't normal in the first year?

Most of what you notice in the first year is the house drying out. Get the things under "Worth reporting" looked at rather than waiting.