Uncategorized

Home / Archive by category "Uncategorized"
Flat Roofs Core Sampling Surveying

Flat Roofs Core Sampling Surveying

Flat roofs are relatively inexpensive and very efficient to keep your buildings and your internal assets covered and protected from the weather. What can you do to identify flat roof defects?

Defects for flat roofs

 

Whilst their relatively low cost for a good protection plays to their advantage, this type of roof is also notorious for defects that often remain unnoticed until it is too late. As with any part of a building, they will be subject to wear and tear and will receive copious amounts of water.  Regular inspection of the roof is essential to make sure that this essential element is in tip top condition and kept free of defects.

One of the most common defects is water ingress which then leads to a leak inside the building. When water ingress does occur on a flat roof, damage often goes unnoticed for considerable time as water slowly penetrates and soaks the decking, insulation and/or structure beneath. This can lead to extensive damage. If left unattended and no leak detection surveying takes place, it can weaken the whole structure and have catastrophic operational and financial consequences for you.

Other defects can occur too. You can read our most popular blog post about the five common flat roof defects here

 

Flat roofs core sampling to detect water ingress

Core sampling allows the surveyor to see the make up of the roof and locate where water saturation may be.

The image above shows what appears to be a roof in a good condition with no obvious signs of moisture ingress, however;  the tenant has been complaining that there are leaks into his top floor office. 

Imagine, this is your tenant. You arrive on site with a surveyor and  the tools for the job, get onto the roof above the leaking office, but where should you start to take a core sample? You carry core samples, one is wet, two are dry. So we know that the insulation is saturated, but to what extent?

Using the roof image above, grab the slider and drag it across the image to reveal the thermal image, in short, red colours reveal saturated insulation (You can find out more about the meaning of infrared colours in our Understanding Colours post.). This  tells you everything you need to know about the accuracy of core samples. By relying solely on core sampling, your surveyor could mistakenly concludes that the entire roof needs replaced or on the opposite, that the roof is sound. How can you know for sure?

If your surveyor is employed by a roofing company, the impartiality of the advice could well be put into question. It is a matter of trust and reputation.

Flat roofs core sampling technique

The method and process of core sampling is therefore important. The core sample technique should be as follows:

  • take one core sample at a high point,
  • take one core sample at a low point and
  • take one core sample mid-way.

Critically this should be at random locations on the roof, not in a straight line. That way the surveyor can find out if water is coming in at parapets and tracking it down, if the area around the outlet is wet as water loves gravity and then try to ascertain the extent of the damage at the mid-point.

The surveyor will take appropriate notes and photographs. Then of course, they must patch the core sampling holes by resiting the sample and sealing the edges. Often this is made using blow torches.

This technique carries high risks for you and for the surveyor:

For you risk of fire from blow torches. Smouldering the flat roof away and causing extensive damage which could cripple your business,

Again for you invalidating roof construction guarantees by cutting holes through potentially perfect waterproofing.

For the surveyor, the risks are inherent to health and safety: slipping on a wet surface, working at height, stand alone working, fire protection, etc.

It is therefore easy to conclude that core sampling should be a last resort surveying technique, just before the nuclear surveying method.

 

Flat roof defects: infrared is the detection solution

If you are an asset manager, estate manager, building surveyor and are being asked to make a budget go as far as possible, then it is essential you get and give impartial advice to the building owner. By investing in an infrared thermographic (IRT) survey,  you mitigate risk from a third party advising whichever solution meets their commercial needs and wants.

Infrared can’t tell the difference between polyurethane and fibreboard. Wet is wet and that effects the temperature on the surface. Why? Simply put, wet insulation doesn’t insulate as well as dry insulation – so heat escapes the fabric. Also because water has a high emissivity. This means that water radiates its energy particularly well when it has finished absorbing it from the sun and from the building itself. This high emissivity makes the wet area appear warm to the infrared thermal camera.

With drones now extensively used to take the thermal pictures, thus eliminating most if not all health and safety risks for the surveyor as well as improving the accuracy of the surveying results, there is little not to like about infrared.

IRT may help you save hundreds of thousands of pounds by turning what you had assumed would be a complete “strip and re-new” into a partial strip and overlay. Conversely however the opposite may be true.

The point being: you will get the truth and if you are interested in delivering value to your clients and managing a sustainable portfolio, that’s an invaluable weapon in your armoury.

Core samples have their place of course. We will always advise you hand your infrared survey reports to your roofing company who may then core and confirm the infrared survey findings. More importantly the core sampling will allow them to establish what the roof is actually made of so that they can propose the appropriate solution for your roof refurbishment.

Do you own or manage buildings with flat roofs? We would like to know what surveying method you favour and why. Drop us a line, give us a call, let's talk all things flat roof surveying.

Innovative surveying technology for built asset management

Innovative surveying technology for built asset management

 

It seems that you can’t move these days without hearing about drones, apps and thermal imaging, but are they truly helpful or just gimmicks? We managed to get almost all the way to 2016 without them.

Like every new industry that erupts from an emerging technology, there are people who take it seriously and do it professionally and those who charge in to make a quick buck. And like every other example in history, the cream rises to the top, the market consolidates and the cowboys are eventually driven out by the sheriff who is usually better known as legislation.

Innovative technology: Thermal imaging

Thermal imaging, or infrared thermography, has - and still is - going through this process. Companies like iRed, Thermascan, Ti and IRT surveys have been around now for more than a dozen years each. There is a healthy respect and competitive market out there. But there are a myriad of smaller companies buying low end equipment, not training themselves properly and going to market with nothing more than a nice looking website. This is why asking the right questions when making your research on infrared companies is important.

Innovative surveying technology: Drones

The same can be said of the drone industry, only it’s 20 years behind the infrared world. It is experiencing a lot of negative press also with an emerging industry to shoot them out of the sky – yep – anti drone tech is also out there. It is a little known fact that over 80% of drone pilots don’t renew their license after year one. It either means the vast majority of the market are novices, or that the failure rate is enormous.

Innovative surveying technology: IoT

The IoT industry is the next big thing for the built environment for sure. If you haven’t come across the anachronism before, it stands for the Internet of Things. Everything from your toothbrush to your fridge will be connected to the net. Lightbulbs will tell you when they become inefficient. HVAC systems will call the engineer themselves and tell him what parts they need, before they brake. Fuses will alert the electrician, or some form of R2D2 unit to repair them before they blow.

When the building itself senses that something isn’t quite right, drones will be deployed to survey a building at night, equipped with an infrared thermal imaging system. Smart meter and sensor technology is moving at an alarming pace. Or exciting pace depending upon your perspective. I love the idea that a sensor will send me a message with GPS co-ordinates to a defectuous building that we can survey and report on.

Innovative surveying technology: Caution required

Huge caution though. Just because things get all high tech and whizz bang, doesn’t make the operative an expert. Interpreting the cause for failure and understanding what the tech is telling you still requires a skilled person. No software will ever replace an experienced RICS qualified surveyor with 20 years under their belt. A sensor or thermal image may say your insulation is 20% saturated on your flat roof - a common defect – the image may point clearly to the origin of the leak but only a human can see that the roofer lapped the felt the wrong way, or didn’t seal the lap joints correctly.

Technological innovation for surveying is unstoppable.

The technology is coming, some of it is here already. It's unstoppable. Best embrace it, swimming upstream is exhausting. But fear not: the dystopian Star Trek world, where no-one has a job and everything is leisure time, is a long way off. De-skilling mundane tasks and de-bugging our built environment will free us up to focus on bigger challenges!

Would you like to know more about how thermal imaging and drones can ease the management of your asset portfolio? Click on the button below to contact us to discuss your surveying requirements and for your free and no-obligation quote.