ROCK BLASTING FAQ

A Rock Blasting Notification will be hand-delivered to advise that blasting activities will soon begin in the nearby area.  All questions regarding blasting activities should be directed to T & A Rock Works Inc. at (250) 765-4811 or [email protected].  

Rock blasting produces ground vibrations, which are measured using seismographs that are set up at homes or structures closest to the blast. Rock blasting also produces air overpressure (air movement) and noise. The air movement, commonly mistaken for ground vibration, can cause windows to rattle, similar to a clap of thunder. This is normal and an expected byproduct of blasting.  

Each blast is designed to achieve lower vibration levels than the industry recommended limit of 50 mm/second PPV. When conducted with proper care and attention, vibrations will not cause structural damage to homes or buildings; however, securing delicate belongings that are susceptible to falling is a beneficial precaution.  

1. Crews may ask bystanders to vacate the danger area – as determined by the Blaster of Record – to ensure the safety of individuals and crew members on site
2. Guards will be positioned around the blast zone to establish a safety perimeter and prevent traffic and persons from entering the danger area
3. Warning sirens are used to signal upcoming blasts: 
   1. 12 short horns indicate that the blast will be detonated when safe to do so
   2. One 5-second-long horn indicates that the blast is over, and the area is safe to enter for T & A personnel
4. The 12 warning horns notify the personnel within the danger area

If you do not hear the warning horns, it is because you are not within the danger area.  

Blasting is a common and safe practice in hillside development and was likely required to provide the services, roads, and foundation for your home, just as it’s required for the homes of your future neighbours. It is quieter, quicker, less disruptive, and less invasive than alternative processes such as rock hammering.

Blasting can occur at any time Monday through Friday between 8:30 am and 4:30 pm and occasionally on Saturdays, if warranted.  

We cannot set specific blast times because it can rush the process and create safety concerns. Blasting requires precision and attention to detail; the careful execution of industry standards ensures that we conduct the safest work for everyone involved. Blast timing varies due to site safety protocols, inspections, and other on-site variables.

As with any damage claim, insurance adjustors require proof of cause. To start the required preliminary investigation process, contact T & A and your home owner’s insurance.

Coast Claims Insurance Services is the independent adjuster engaged on behalf of the insurers of T & A. Please make initial contact with T & A Rock Works Inc. prior to contacting Coast Claims. 

Pre-blast surveys are conducted by local, third-party companies on properties in close proximity to the blasting location(s). Pre-blast surveys are not conducted on properties outside of the determined close-proximity radius from the blasting location(s).

Homeowners can refuse to have a pre-blast survey conducted, but it is not recommended. Refusal to participate in a pre-blast survey will be documented for insurance purposes.

Blasts are conducted in accordance with the Best Practices Guide for Close Proximity Blasting Operations. The Western Canada Chapter of the International Society of Explosive Experts (ISEE) created and maintains the Best Practices Guide to ensure trained professionals use charge weights that are appropriate for the distances to nearby structures.  

Independent consultants provide oversight on the ground vibration data of every blast and the management at T & A continually analyze the data and adjust, when warranted.  

Blast design parameters can change from day to day and blast to blast, which is why some blasts may feel different than others. Variations are normal and expected and can be related to the number of total blasts, charge weight per delay, blast direction and/or timing, geological characteristics, blast site location, weather, depth of rock cut, etc. 

We receive permits to blast within municipalities. If, for some reason, blasting must continue beyond the permit limit, we must renew or re-apply for another permit. In such a case, we will provide you with an update before the next blasting period occurs.