WHY ARE MY WALLS CRACKING
When we notice cracks on our walls we think that maybe the house is going to collapse and that it signifies a structural defect,not all cracks are structural as some cracks are signs of a serious defect while others are just settlement crack -Cracks on my walls are common in Melbourne
There so many answers to the above question:
The majority of cracks are caused by moisture in the soil, this can be caused by storm water overflows gutters blocked ,surface water flowing back to foundations, vegetation-there so many different factors that will be investigated to find the actual cause
One of the most common factors affecting foundations are trees and shrubs placed too close to the foundation edge and this is the most common cause of settlement as the vegetation will affect the moisture levels of the soils thus creating movement and rotation of footings.
Too much surface water will cause heave so its important to alleviate surface water ponding near footings
Recent inspection we conducted was on a new home development in Melbourne suburb of Chirnside Park,it was a two unit development and the front land was sloping towards the house.
There was no drainage provided to remove surface water and there were no temporary downpipes connected to up stands causing the water to pond along the foundations, this was not rectified for over 6 months due to building dispute with owner.
This may cause significant foundation problems in the future and will require monitoring by the owner.
We got a call to inspect a property in Caulfield recently with problem being cracks to outside walls.
The unit was part of a 2 unit development ,brick veneer property with concrete stumps and strip footings
There was vertical cracking at the front window sill approx. 15 mm in width going down to foundations,also cracking above laundry door at lintel and to 2 other corners of house.
Our inspection to sub floor discovered dampness of soil throughout,this property still had the old earthenware pipes that are susceptible to cracking over time and dislodging due to soil conditions.
We recommended that the owner should contact our plumber to provide a CCTV camera survey report as we believed the problem to be blocked or broken storm water pipes that was causing the moisture in the soil to become elevated.
The survey report showed that the problem being the storm water pipes which were required to be removed and replaced at considerable cost to owner.
Underpinning was also going to be required at a latter stage to rectify all cracking .
Cost of underpinning plus plumbing was $18,899 plus GST a lot of money especially if you don’t have it.
This could have been alleviated if the owner had organised a pre purchase building inspection prior to purchase of property saving himself thousands.
A pre purchase building inspection conducted by Registered Building Practitioners is well worth the small cost giving you peace of mind that all is good with your purchase and there are no structural issues that will cost you thousands to rectify.
Corner Settlement Cracking.
When footings move, they may heave or settle ,settlement is more common as corners are the first to show distress with consequent cracking around openings, heave located close to corners will have similar symptoms.
Wall cracks fall into three Major classes:
1/Interior wall cracks for example cracks at the plasterboard or gyp rock;
2/Exterior wall cracks like cracks in the brickwork, surface or rendering of walls;
3/Cracks in foundation walls.
All three could be severe and symptomatic of structural collapse. How severe the issue is can only be evaluated by studying:
The positioning of the wall crack;
Whether it’s a jagged, flat or vertical wall crack;
Whether there’s separation from the materials used to build the walls or separation of the wall out of the frame;
Exactly what led to the wall crack;
Whether the cause is continuing and/or whether there’s very likely to be a recurrence down the track
Gaping fractures are an indication of a severe structural issue.
Zig-zag fractures or stair-step cracks from the mortar line from the brick walls of your premises may point to a structural flaw on your premises.
The issue may be especially serious when you’ve got a whole separation from the cement or mortar between bricks.
If it is possible to see through a fracture or if a broken brick can be wiggled or eliminated is definitely time to predict the pros as a matter of priority.
Tracking down the cause or causes of wall cracks is your very first step in creating any assessment regarding the seriousness and expense of fixing wall cracks. Probably causes may include a few of the following:
Some level of excavation of the soil is generally necessary when a house is first constructed.
Just how much excavation will be required will vary with the kind of house you are constructing.
Some kinds of homes need more dirt disruption than many others in the class of their structure especially if your land is steep.
This procedure can take weeks or months to happen. Natural settling will frequently cause narrow vertical cracks instead of large jagged cracks which is not an issue
When foundation conditions vary from one side of a footing to
another, the footing may rotate and rotate the wall it is supporting.
Small rotations in footings can cause major distress at tops of walls; a 1 mm rotation in a 450 m
deep footing will grow to a 7 mm gap at ceiling level, usually seen at the cornice.
A common cause of such rotation is a change in foundation moisture, which may
fluctuate on the outside of the footing but be comparatively stable on the inside.
Most building structures effectively resist inward rotation, so it’s the outward
rotation that produces the distress we see.
Also,in the case of cyclic movement, the crack will distress and resist closure, repeated inward
and outward footing rotation .
Cracking to wall structures is not an easy defect to remedy and finding the cause is not as easy as it seems and will require an intense inspection of the property .