Demolition Techniques

Demolition Techniques
You may assume demolition is simply blowing things up. Some involve explosions but it is however way more technical than that. There are various demolition techniques that are considered as ‘demolition’.

 

It must be noted that before any demolition takes place the following practices need to be completed according to The Constructor

1. Surveying
2. Removal of hazardous materials
3. Preparation of plan
4. Safety measures

 

Taking the above into account the following (according to Civil Engineering News) are selected.

1. Non Engineering Demolition also known as Manual.

a) Refering to tools such as Sledge Hammers, Jack Hammers and Drillers which are used by workers.

Jackhammer - Demolition Techniques.jpg
Jackhammer Technique

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Engineering Demolition which is split into 3 categories.

a) Mechanical Method:

Wrecking Ball (think Miley Cyrus but without the theatrics)

Pusher Arm technique (a specialised hydraulic arm used for smaller buildings)

Thermic Lance Technique (using flaming temperatures of 2500 0C to melt reinforcement)

Non-Explosive (drilling and filling with expanding slurry)

Concrete Sawing

Deliberate Collapse (significant structural items are removed)

Pressure Jetting (thanks to H20)

 

b) Implosion: Inward disintegration using explosives

c) Deconstruction: Non-structural and structural

Wrecking Ball - Demolition Techniques.jpg
Wrecking Ball Technique

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Demolition encompasses many techniques and is often used in conjunction with new construction or renovation.

In conclusion, I’ll take inspiration from Rumi, ‘In this life many demolitions are actually renovations.’

 

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About Sasha Anderson

Millennial Mom + wife living the hash-tag life. Remember: If You Fail - Fail Forward

Featured Tender: Demolishing, Refurbishment and Construction of New Facilities at Mbatini Lower Primary School (Phase 1)

Demolishing, Refurbishment and Construction of New Facilities at Mbatini Lower Primary School (Phase 1)

Demolishing, Refurbishment and Construction of New Facilities at Mbatini Lower Primary School (Phase 1)

Contract Number:

PWRT/2368/18MP – Department of Public Works Roads and Transport

Description:

Department of Public Works Roads and Transport Nelspruit invites tenders for Demolishing, Refurbishment and Construction of New Facilities at Mbatini Lower Primary School (Phase 1) in Mkhuhlu, Culcata C Bushbuckridge Local Municipality.

Category Industry
Demolition & Blasting, Building Institutional, Renovations
Region Site Inspection
Mpumalanga 2018-06-21 11:00 AM
Closing Date Contract Period
18 July 2018 at 12:00 No Details

 

 

If you are a valued Tender subscriber, you can find more details about this Tender here
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About Lauren Davids

I am a Content Researcher for the Western Cape Region in the Tenders South Africa Department.

Featured Project: Transnet Pipelines – Kroonstad Depot

Description: Construction of the fire protection system upgrade, inclusive of demolition, civil, structural, building, mechanical, electrical, instrumentation and control system supply, installation and commissioning at the Kroonstad Depot in Free State. CIDB8ME

Status: Tender

Industry: Industrial

Region: Kroonstad

Sector: Public

Value: R61 Million – R100 Million 

Timing: 2018 onwards

If you are a valued Projects subscriber, you can find more details click here

About Bianca Warwick

I had the privilege of joining the Leads 2 Business content team in January 2012. I work in the exciting Projects department, following the progress of construction developments in KwaZulu-Natal and the Free State.

L2B Blog: Renovation or Demolition?

posted in: General 4

The defining line between renovation or demolition:

Here is a question that is posed to me at least once a month – “Do I renovate my existing home or do I demolish it and start from scratch with a new build?”
There are plenty of reasons to consider demolition. You may be looking to free up land, or perhaps you’re working on a major building refurbishment and need to change the layout.
There is a fine line when you are renovating where you need to know if you’re going to start wasting money fixing a house that is not worth fixing.
If your home is structurally sound, the outer shell of the home has been properly maintained (the roof, the siding/brick and the foundation) and it was properly done at the time of the construction then there is probably no need to demolish it.

Two ways you could demolish a building structure:

1. Explosive Demolition
2. Non-Explosive Demolition

  • Sledge hammer
  • Excavators and Bulldozers
  • Wrecking Balls
  • High Reach Excavators

 

Things You Should Know About Demolition

1. Demolition – So how do you demolish a building or home? Before you take down all or part of a building, you will have to apply to the Building Department for a demolition permit. The process is much the same as for a building permit, but some special situations may affect your application. In a demolition control area, for example, you will not be able to demolish a residential property until you have received a demolition permit issued by the municipal council.

 

I say the best way to demolish a building is also known as strip-out, this process is very popular right now. As recycling and salvaging of material are very attractive to builders during these days, allowing them to re-use material or recycle it. Selective interior/exterior demolition or recycling of wood, brick, metals and concrete are all recycled for future use in new structures blending the old with the new. This demolition process is not limited to removal of interior equipment, walls, floor, ceilings and exterior components. The main purpose of this method is to recover the maximum amount of primarily reusable and secondary recyclable material in a safe and cost-effective procedure. Although it is a labour intensive process and can be very difficult to achieve in a timely and economical manner for light framed buildings. Demolition may very well be the most exciting and speedy phase of construction. For a complete demolition, a home can come down and be entirely removed from the site in a day or two.

 

Question: I want to demolish my house and there are items like flooring and windows that may be reusable. Who do I call?

Answer: Find a demolition company that actively recycles the whole building. Most demolition companies crush materials with large machinery and cart it away. If you have good quality reusable materials like timber flooring, heritage bricks or period architectural features it’s worth looking for alternatives. Have a look at http://www.enviroserv.co.za/industries/construction

  • Woody and plant materials
  • Concrete
  • Gravel, aggregate, stone, and rock
  • Masonry and rubble
  • Metals (ferrous and non-ferrous)
  • Wood
  • Plastic
  • Glass
  • Doors and windows
  • Asphaltic roofing, Plumbing fixtures

2. Renovation – What is Renovation (also called remodelling)? It is the process of improving a broken, damaged or outdated structure. Renovations are typically either commercial or residential. Both remodelling and renovating mean to make improvements on an existing building or home. However, they refer to two slightly different types of construction. Renovation means “restore to a good state of repair”… Remodel means “to change the structure or form of something”.

 

If most of the changes that you want to do are inside the house and are more cosmetic, then you should rather think about renovating. Tearing down interior walls and moving plumbing and heating lines is not that big of a job and can be done on a moderate budget. With new dust stopping protection and floor protection, a lot of the work can be down without causing damage to the rest of the house that isn’t being altered. Plus this allows you to leave your furniture and other possessions in the house while it’s being worked on.

If you want to add square footage, adding an addition or several additions can easily be done, as long as you have adequate space on your property. Additions are an easy way to make your house more enjoyable and add value. It allows you to do something completely different than the rest of the house which would allow you to leave more of the original features in the existing house. This would allow you to bring a modern touch at a lesser cost than trying to reshape the whole existing interior.

 

3. Renovation or Demolition?

One of the big advantages of renovating rather than demolishing and building from scratch is that in some cases you can do it in stages – and still have a roof over your head for most of that time. Don’t forget to consider where you’ll live when you’re building or renovating, and how much that may indirectly add to the cost over the duration of your build.

If you’re demolishing or renovating, you may be able to recover at least some of your costs through salvage and recycling too

 

4. Steps to Planning a Renovation

A. Choose a design professional. To create a plan and detailed scope of work, most homeowners hire either an architect or interior designer, sometimes both. Many designers work on projects that don’t involve major structural work or additions and also offer assistance with material and colour selections. Architects may take on a wide range of work, or work only on floor plans and permits and leave the details of the electrical plan, baths and kitchen to another designer.

B. Interview contractors. Contractors are frequently brought into the process once a final design has been selected. Usually, there is at least a general idea of how the home will look from the outside, a dimensioned floor plan and some preliminary material selections. With this much information, it’s possible to provide preliminary estimates of cost.

C. Get your permits. Depending on the scope of your project and where it’s located, permitting can take a day, months or even years.

 

Sources:

https://www.homebuilding.co.uk/renovation-your-step-by-step-planner/
https://mg.co.za/article/2014-06-12-to-refurbish-or-not-to-refurbish
https://www.justlanded.com/english/South-Africa/South-Africa-Guide/Property/Renovation-Restoration 

http://www.build.com.au/should-i-renovate-or-demolish
https://theconstructor.org/structures/demolition-methods-process-buildings-structures/13941/

Bulldozer demolition image

About Nirasha Rampersad

I started working for Leads to Business June 2017 as Support Assistance in L2Q.

Did you Know #DYK: Demolitions gone wrong

posted in: Did You Know 0

One of the earliest documented attempts at building implosion was the 1773 raising of Holy Trinity Cathedral in Waterford, Ireland with 150 pounds of gunpowder, a huge amount of explosives at the time. The use of low-velocity explosive produced a deafening explosion that instantly reduced the building to rubble.

There is no actual date when demolition started and how they had demolished castles and other types of structures, but in our times we see demolition every day. I was under the impression you plant your dynamite, press your button and BOOM! Not knowing how much knowledge is required for demolishing a structure, or the different types of demolishing techniques there are. For instance, for smaller houses or small buildings large hydraulic equipment, cranes and bulldozers can be used. Large buildings, bridges, tall chimneys and smokestacks can be demolished with explosives. A new approach to demolition is the deconstruction of a building with the goal of minimizing the number of materials going into landfills, this is called the “green” approach. This is applied by removing the materials by the specific type of materials and segregating them for reuse or recycling. The Japanese company Kajima Construction has developed a new method of demolishing buildings which involves using computer-controlled hydraulic jacks to support the bottom floor as the supporting columns are removed. The floor is lowered and this process is repeated for each floor. This technique is safer and more environmentally friendly and is useful in areas of high population density.

However interesting demolition is, if not done correctly the outcome can be devastating. In fact, any error could be disastrous as it could severely damage neighbouring structures. Flying debris could harm onlookers, a building that fails to collapse completely may be unstable and could be difficult for workers to approach and then of course air overpressure that occurs during the implosion. If the sky is clear, the shock wave (a wave of energy and sound) travels upwards and disperses, but if cloud coverage is low, the shock wave can travel outwards, breaking windows or causing other damage to surrounding buildings. In regards to this, let’s take a look at some demolitions gone wrong:

 

2013 Philadelphia building collapse

On 05 June 2013, a building undergoing demolition collapsed onto the neighbouring Salvation Army Thrift Store at the southeast corner of 22nd and Market Streets in Centre City, Philadelphia, Pennsylvania, trapping a number of people under the rubble. The store was open and full of shoppers and staff. Six people died and fourteen others were injured. The construction contractor, Griffin Campbell, an excavator operator, Sean Benschop, was charged with involuntary manslaughter and other charges. They were found guilty of manslaughter, and Campbell and Benschop received prison sentences of 15 years to 30 years, and 7.5 years to 15 years, respectively.

On 12 June 2013, Ronald Wagenhoffer, the 52-year-old City Department of Licenses and Inspections inspector responsible for inspecting the demolition site, was found dead in his truck with a gunshot to the chest. His death was ruled a suicide.

 

Royal Canberra Hospital implosion

   

 

The Royal Canberra Hospital implosion was a failed building implosion that killed one person and injured nine others. The implosion occurred on 13 July 1997, when the city’s superseded hospital buildings at Acton Peninsula on Lake Burley Griffin (that formerly constituted the Royal Canberra Hospital) were demolished to make way for the National Museum of Australia. The main building did not fully disintegrate and had to be later manually demolished. But far worse, the explosion was not contained on the site and large pieces of debris were projected towards spectators situated 500 metres away on the opposite side of the Lake, in a location that nobody considered unsafe or inappropriate. A twelve-year-old girl, Katie Bender, was killed instantly, and nine other people were injured. Large fragments of masonry and metal were found 650 metres from the demolition site.

 

In cases of demolition gone wrong, these demolition failures did not only cause destruction to near surrounding buildings or the loss of reputations, but the cost was so much more, the cost of lives.

In order to practice the phenomenal art of demolishing, one must always have the necessary qualifications and truly know their story.

 

Sources

https://en.wikipedia.org/wiki/Building_implosion

https://en.wikipedia.org/wiki/Demolition#Manual

https://en.wikipedia.org/wiki/Building_implosion

Canberra Hospital image

Canberra Hospital Memorial stone image

Philadelphia building collapse image

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About Jackie Thomas

I started working for Leads 2 Business in February 2017. I work in the Daily Tenders division where we source and capture daily tenders for our subscribers. It is an absolute pleasure being a part of this Company and I look forward to being apart of this company for many years to come.

L2B Blog: How to demolish a wall the right way

So when I got my topic for our blog I thought to myself, how am I supposed to know? Well seeing as though we’re in the Industry and get to work with the Pro’s on a daily basis, why not ask them how they do it? I reverted to my client Mr Brenton Bokelmann from Supa Diggers. With his great sense of humour, his first response was “drive the machine through the wall”

Please note, it is imperative to use the proper tools. Employ care when demolishing the wall to steer clear of injury. Wear the relevant PPE (Personal Protective Equipment) such as safety glasses, a dust mask, heavy duty gloves and safety boots.

First things first! Everyone dislikes a mess and extra work, so best you clear out the room or the area where the wall is and place a plastic covering for minimal cleanup time and effort.

Knowledge of the simple basic construction craftsmanship and knowledge with power saws and power hammer drills is convenient when demolishing the type of brick wall found in and around a home in South Africa.

For your regular buildings, such as houses, that are one, two or three stories high, demolition is quite an effortless process when you don’t have close by buildings etc. The wall is pulled down either physically or by using yellow hydraulic equipment: cranes, bulldozers or excavators.

Size Matters! If you have a neighbour to bear in mind and don’t necessarily want your debris lying in their dining area, break down the wall piece by piece ensuring the wall doesn’t come down all at once, causing damage to surroundings. Begin by measuring and marking the area of the wall you want to be removed, doing this you create a breaking point for your wall. Score over the said marks with a utility blade that is sharp. This prevents unwanted wall breaking or being demolished in error. Then slowly take it down piece by piece Either with your sledgehammer or excavator depending on size.

If it is a load-bearing wall, in other words, it keeps the roof in place, best you be ready to first remove the roofing in that specific area.

“A brick wall is as easy as pushing it over with an excavator and when it falls it breaks into manageable sizes so that you can move the debris,” Brenton says. If the wall has items such as electrical cables, plumbing or gas lines you will require a professional to come out and give the relevant permissions for you to be able to go ahead.

Final step, remove and dispose of all debris from the demolition in a safe and responsible manner

Thank you for reading my blog, please subscribe to receive our Building and Construction News e-mails which include the blog articles, for more amazing industry related blogs by my dearest colleagues.

 

Sources:

http://homeguides.sfgate.com/demolish-brick-wall-23306.html

http://www.diynetwork.com/how-to/make-and-decorate/decorating/how-to-basic-wall-demolition

Brenton Bokelman from Supa Diggers

https://en.wikipedia.org/wiki/Demolition

About Julia Smit

I am 25 years of age and a Dynamic entrepreneur who utilizes creativity, leadership and teamwork to design and execute solutions that create customer value. I am an effective communicator with the ability to create a prospective customer into an actual customer. Experienced professional with planning and organizational skills that balance work, team support and ad-hoc responsibilities in a timely and professional manner. I am a New business development executive with 6 years of experience in sales, customer care, business growth and expansion. I take my career at Leads 2 Business very serious am super passionate about what we do.