# Forum Home Renovation Brickwork  polyurethane injection - uretek

## btio

Hi
This is my first post. I'd like to ask your opinion about the polyurethane injection to fix the brickwall cracks. 
There are about 1mm brickwalls cracks in few places . It is a 50 yr old brickveneer unit. The zigzag cracks have been there for several years.
I read about uretek polyurethane injection at the internet. It doesnt need any excavation, and can be done within half day.
It may be cheaper than the conventional underpinning. 
Does anyone have any experience with polyurethane injection? What do you think about this techonology? 
Thanks
btio

----------


## Bloss

Not experienced with that brand, but the first question is what has caused the cracks. 1mm isn't all that large as cracks go so I doubt any major engineering fix is needed. In any case a urethane filler is neither structural nor a replacement for underpinning if that is what is needed. 
Urethane will give a flexible fill that can be painted and will allow the cracks to open and close without becoming as visible, but the that does not fix the structural failure that is allowing the movement - usually underspecced or failed footings in a reactive (clay) soil. 
In a 50 year old house it is more likely just that the foundations were a little undersized for the soil type. If 1mm cracks that have been stable for some years is the only problem then no major work should be needed - so choose a suitable flexible gap filler - just don't believe anyone that tells you their injectable product can replace engineering work. But that's only from your post - really needs a visual assessment by someone who knows what they are seeing.

----------


## Danny

Brick cracking is a widespread and potentially very expensive problem but, strangely enough, one that most householders seem reluctant to spend money on to obtain a proper professional diagnosis. Fortunately, your case appears minor; at this stage!
Most house cracking is due to natural causes, primarily climate influenced deminished reactive subsoil moisture content.  
Under no circumstances should you proceed with injecting subsoil with an artificial replacement for good old H2O (if indeed the lack of is the problem) without first outlaying some cash to get a report from a suitably qualified geotechnical engineer. The money spent may well save you money on a suitable qualified recommended  alternative treatment. 
House cracking can be a complex matter and the cause is not always found at the problem area; it could be on the other side of the house for example!
Quality information and statistics can be sourced from linked sites at: SUPADIVERTA - syphonic rainwater diverter - click on House Cracking under the GARDEN heading. 
The Archicentre press release archives are also well worth a look. Archicentre is linked at Supadiverta. 
Do not overlook your local shire engineer as a valuable source of information and a good person to recommend a suitably qualified geotechnical engineer.

----------


## Master Splinter

Uretek isn't a cheap process either - they generally don't get out of bed for a job for less than $5k.

----------


## Danny

Just entered Uretek into the forum's search facility and a lot of information about brick cracking comes up. 
One reply was from Graeme Cook to the thread: To repair drought damage or not?, posted 30/10/2008 at Structural Renovation, Roofing, Demolition etc. Well worth reading, as are many of the others. 
Uretek website recommends householders get an independent qualified assessment and that Uretek will work with that person. Their personnel also includes appropiate highly qualified engineers.

----------


## jrggv

I had a problem with subsidence, where a previous owner's extension was sinking relative to the rest of the house.  Got Uretek injected under the slab.
True - it cost several thousand.
Also true - it took a couple of hours, no disturbance to anything, and the problem was fixed (with a long warranty).
But I wouldn't do it for 1mm cracks - I had a few 5mm cracks, but more importantly one whole room was skewing out of square.  Sliding doors shut at the bottom, still showing daylight at the top.  They were able to calibrate the whole repair while they did it: measured a 30mm difference in floor level before they began, and they pumped the house up by 26mm until it was flat (enough) again.  I was amazed at the precision they could achieve.

----------

