What causes loose, cracked and crumbly grout?

Loose, crumbly or cracked grout is not only an unsightly blight on your tiled floor, but also can lead to extensive issues with your tiles as well. Once a grout line crack or begins to come loose it can quickly spread throughout your entire floor and soon you will have tiles moving and lifting.

So what is it that causes grout cracking or crumbling?

Improper Installation

One of the main causes of grout deterioration or cracking is poor installation. Tilers will often make the mistake of not putting the correct amount of pressure on the grout line when applying the grout to tile joints. This can mean that the grout does not fully penetrate the full space and as a result ‘bridges’ over the gap rather than filling it. This is an issue frequently found in wall tiles and can cause a potential hazard in your home especially if the issue occurs in an area populated frequently by people such as a shower or walkway.

A ‘bridged’ grout line is weak from the outside and can be hard to detect until the tile becomes loose. If you notice any holes or gaps appearing in your grout lines, be sure to get them removed and re-filled by an expert.

Grout is too ‘wet’

A grout mixture made with too much water or polymer additive can ultimately cause weak grout lines once dried. The moisture in any grout mixture must ultimately evaporate, and if there is too much moisture in the batch, this evaporation will lead to weak spots in your grout once dried.

Grout left too long to cure

Another common issue with grout is the habit of leaving the grout in the bucket too long, which causes the grout to ‘cure’ prematurely. Often tilers will try to make a large bucket of grout to save time only to realise the bottom of their bucket is full of hardened grout mixture. Often a quick fix is too add water to loosen the mixture, however once the grout has cured it will struggle to form a solid block once packed into the grout lines, leaving your grout lines weak and crumbly.

Substrate Movement

Changes in temperature, warping of timber floor or moisture coming up through a concrete foundation can often cause huge shifts in the substrate which will inflict great amounts of stress on your grout lines and tiles. Often the grout lines will give way first, especially if any evidence of the above symptoms is shown, however sometimes the tile will shift first which in turn will wreak havoc on your grout lines.

The best solution for dealing with substrate movement is to create strategically placed expansion joints throughout your home to allow for movement and take the pressure off your grout lines and tiles.

So what can I do?

For any grout related issues, the answer is not to patch over the affected areas. This will ultimately lead to further deterioration within the grout lines. The key is to fix the issue at the source to avoid any further issues with tile movement or cracking. If grout lines start to crumble or crack talk to our expert team at Barefoot Floors for diagnosis and a quick and easy solution for your home.