What causes new build settlement cracks and how do I minimise them?

Most homes will experience minor cracks at some point, no matter how well-built they are. The majority of cracks appearing in homes throughout the UK are not normally serious and are unlikely to affect the stability of the property. However, understanding the types of cracks that may appear in newly built homes is crucial for homeowners.

Hairline cracks are common and often occur around door frames and windows due to minor shifts.

It’s important to differentiate these from more concerning cracks, such as subsidence cracks, which could indicate huge structural integrity issues with the property. Factors such as clay soil, water leaks, tree roots, fluctuations in temperature, and moisture levels can also influence the extent of cracking.

If you’re an owner of a new-build home and you’ve noticed cracks appearing, continue reading our helpful guide to discover how cracks appear, what you can do to minimise them, and what to do when you discover large cracks.

How do new home cracks appear?

There are several reasons why cracks may appear in a newly built home, including drying shrinkage, moisture or thermal changes in building materials, and ground settlement.

Thermal movement

Thermal movement is related to seasonal and weather changes.

All buildings will shrink and expand as the humidity, moisture, and temperature fluctuate throughout the year.

The different building materials within a property react differently to seasonal changes and small movements throughout the year can cause minor cracks in the home.

While these cracks are not structurally impactful if they’re left unattended for several years, there is a possibility that they could increase in size should moisture enter the cracks.

Consistent change in temperature causes timber to expand and shrink, which can lead to small cracks in joints, skirting boards, and architraves. This can also lead to hairline cracks showing on ceilings.

Shrinkage cracks

Shrinkage cracks occur during the initial drying-out period for new-build homes.

Many building materials contain water when they’re used during construction, so they can shrink as they dry – leading to minor cracks in floors, walls, and ceilings.

These types of cracks are usually horizontal or vertical and have a consistent width of no more than 2mm.

Moisture movement

Cracks caused by moisture relate to the moisture levels within the property. Water vapour is created when the inhabitants of a home breathe or carry out everyday activities, such as showering, washing and drying clothes, and preparing food.

New-build homes are designed to restrict cold draughts and prevent heat escaping, but by doing this, they also reduce water vapour escape.

Instead, the building materials will absorb this vapour, causing them to expand and create small cracks.

New build settlement cracks

Homes can experience cracking as it settles on new foundations. The ground beneath the property can compact under its weight which causes the building to move.

This sounds quite alarming but the settlement is often minimal and it stabilises after a few months.

Like shrinkage cracks, a settlement crack is often no more than 2mm in width and shouldn’t affect the structural integrity of your home.

Find out how to fix settlement cracks later in this guide.

Subsidence cracks

Subsidence cracks appear after the ground beneath the property. Movement can happen because of clay soil, tree roots, and vegetation.

Poor drainage, weak ground. and mining activity close to the property can also lead to subsidence.

How to minimise new home cracks

Are there ways to minimise cracks? Yes, there are!

In terms of heating and ventilation, here are steps you can take to prevent cracks from appearing or, if they’re already visible, from getting worse.

• Keep an even temperature throughout the property.
• Keep your home well-ventilated so moisture can effectively evaporate while the new-build structure dries.
• Use the central heating system sparingly after first moving into your new home so the structure can warm and dry gradually.

Trees are also a big consideration when trying to minimise the risk of cracks. If you’re keen to plant trees on your property, be careful what you choose because it can affect the structure in later years.

This is because trees demand a lot of water which can cause significant ground movement if they’re planted too close to the property.

As such,ou should allow enough room for trees to grow safely; tree roots can grow much further than you would imagine.

It’s also a good idea here to consider your neighbours before planting trees. You may plant them far from your property, but will that affect your neighbours in later years?

What to do if you find cracks

Waking up to a crack in your home can be alarming, but – often – it’s not as bad as it looks.

In most cases, a house hasn’t suffered from any major issues like excessive new build settlement cracks or subsidence.

However, if you think your property is at risk, you can measure how wide the crack is with a ruler or tape measure. If you don’t have these to hand, you can measure the crack with the width of a pound coin, which is around 3mm.

Cracks that measure 2mm or less are normally regarded as cosmetic, will not affect the structural safety of your home, and can often be repaired with some filler.

When to contact a professional structural engineer

Of course, some cracks warrant professional assistance. You should contact your insurance provider who will send a professional structural engineer to inspect the cracks if they are:

• More than 5mm wide at any point
• Wide at one end and narrow at the other
• Vertical or horizontal and width is consistently more than 2mm
• Is diagonal or in the shape of stairs climbing the wall or ceiling
• Is visible both inside and outside the home
• It runs horizontally along the line of the damp proof course
• It extends below the damp proof course
• Is accompanied by changes to windows and doors, such as, if they’ve started to stick or the frames swing open
• If the crack has widened or lengthened since you first found it

Get an ABC+ Warranty new build warranty

At ABC+ Warranty, we offer a huge range of structural warranties for buildings of all sizes and types – including a new home warranty.

This particular warranty covers new build homes for up to 10 years, separating into two different types of coverage; the first two years hold the developer liable for any repairs and the final eight years are more insurance-based.

If you’d like to know more about how our new build warranty can protect your building, then you’ve come to the right place. We can give you all the pointers you need, so you can be sure that you’re choosing correctly with us.

Give us a call at 0161 928 8804 or email info@architectscertificate.co.uk. You can also fill out our online enquiry form and a member of our new build warranty team will get back to you as soon as we can.

Thanks to our no-obligation quotations, you’ll never have to commit to a higher price than you’re looking for or worry about new build settlement cracks causing you too much stress.