Currently, mass timber building designs commonly incorporate a concrete floor topping. This can improve building accoustics by increasing the mass of the assembly, reduce floor vibration and create a smooth flat surface to install finish flooring on. The installation of concrete requires formwork, pouring and finishing the concrete and time to cure which adds to project schedules. One way to address this is to use mass timber elements that are prefabricated with concrete toppings preinstalled. Replaceing the concrete floor toppings wiht dry alternatives, such as cement board, may also reduce construction timelines, while still ensuring adequate acoustic and vibration performance. Cement board needs only to be screwed in place and can be walked on immediately after installation; this reduction in construction time may reduce overall project costs and help make wood buildings more cost competitive than other types of construction.
Evaluating a selective harvest operation as a forest fuel treatment as a forest fuel treatment. A case study in a mature douglas-fir forest in central interior British Columbia
............................................................................................... 5
List of tables
Table 1. Potential for crown fire initiation at 90th
percentile conditions
The City of Quesnel, B.C. has applied an innovative selective harvesting technique in a mature Douglas-fir forest stand with the objectives of maintaining biodiversity and reducing fuel-load buildup and consequent wildfire threat. FPInnovations researchers monitored and documented the harvesting operations and measured machine productivity to evaluate the cost-effectiveness of the operation.
To support the assessment of fuel-load reduction, FPInnovations’ Wildfire Operations group conducted pre- and post-harvest fuel-sampling activities to evaluate changes in forest fuel components.
A fuel amendment treatment is proposed as a technique that can allow prescribed burning in hazardous fuels during low to moderate fire hazard conditions to minimize the risk of fire escape. In August 2017, a fuel amendment technique was applied at the Fort Providence Wildfire Experimental Site. In October 2019, a burn trial was conducted in a plot treated with the fuel amendment technique and fire spread to adjacent fuels was documented. Future documentation at this site will include assessing crown mortality to determine the effectiveness of the treatment.
This study investigated the effects of applying three mulch treatment intensities on fuel bed characteristics and the resultant fire behaviour. This is a companion report to a previously published report titled Mulching productivity in black spruce fuels: Productivity as a function of treatment intensity. The findings of these fire behaviour trials, in conjunction with productivity results, can assist fuel management practitioners in developing appropriate cost-effective mulching prescriptions.
Recent crown thinning in a boreal black spruce forest does not reduce spread rate nor total fuel consumption, results from an experimental crown fire in Alberta, Canada
A 3.6 ha experimental re was conducted in a black spruce peatland forest that had undergone thinning the year prior. After 50 m of spread in a natural stand at 35–60 m min-1, the crown re (43,000 kW m-1 intensity using Byram’s method) encountered the 50% stem removal treatment; spread rates in the treatment were 50–60 m min-1. Fuel consumption in the control (2.75 kg m-2) was comparable to the treatment (2.35 kg m-2). Proxy measurements of re intensity using in-stand heat ux sensors as well as photogrammetric ame heights had detected intensity reductions to 30–40% of the control. Crown fuel load reductions (compensated by higher surface fuel load) appear to be the most signi cant contributor to the decline in intensity, despite drier surface fuels in the treatment. The burn depth of 5 cm in moss and organic soil did not di er between control and treatment. These observations point to the limited e ectiveness (likely reductions in crown re intensity but not spread rate) of stem removal in boreal black spruce fuel types with high stem density, low crown base height and high surface fuel load. The observed re behaviour impacts di er from drier conifer forests across North America.
Fire behaviour; boreal; crown re; fuel treatment; thinning; black spruce
