Green roofs have seen huge growth in North America over the past few years, but have been an established practice in Europe for decades. They offer many benefits for the environment including storm water retention, reduction in energy consumption and reduction in the urban heat island effect. In addition they help to extend the membrane life and improve the aesthetics of the building. There are two green roof categories: Extensive and Intensive.
Extensive green roofs are generally lower in weight and cost and require less plant maintenance. With only a few inches of soil, extensive green roofs typically support plants that are tolerant of high heat, drought, wind and frost like grasses, wildflowers and moss. Extensive roofs are often used in areas that will not be subject to regular traffic.
Intensive green roofs are generally heavier, cost more and require more maintenance. However, because the soil is deeper, intensive green roofs can accommodate trees, shrubs, bushes and vegetable gardens. It is not uncommon to see an intensive green roof used for recreational purposes.
Vinyl membranes are ideal for all green roof applications. They have a proven history of lasting in adverse conditions and their heat welded seams are actually stronger against roots than ordinary membrane. In certain situations the membrane is laminated or coated to protect against mold/fungus/bacterial build-up. To learn more about vinyl green roofs,click here.
Thursday, September 6, 2007
Wednesday, September 5, 2007
Plaza Decks
Plaza decks are public areas accessible to pedestrians and in some cases vehicles that are located at or above grade level. They provide a functional or aesthetically pleasing element to any construction project which, at first glance, may not look like a waterproofing project.
A waterproofing system is used underneath a plaza deck overburden to protect the structure, occupants and the property beneath them from water and moisture penetration. Plazas incorporate durable wearing courses such as pavers or concrete, and often times integrate appealing architectural elements such as landscaping, lighting, railings, fountains and pools.
Learn more here.
A waterproofing system is used underneath a plaza deck overburden to protect the structure, occupants and the property beneath them from water and moisture penetration. Plazas incorporate durable wearing courses such as pavers or concrete, and often times integrate appealing architectural elements such as landscaping, lighting, railings, fountains and pools.
Learn more here.
Thursday, August 30, 2007
Waterproofing – A Growing Industry
Waterproofing is the treatment of a structure to prevent the passage of water under hydrostatic pressure. Waterproofing on a roof surface is still a waterproofing project, despite its location. The difference between roofing and waterproofing is whether or not the membrane is covered or protected by overburden (dirt, pavers, etc.). Two common types of waterproofing projects are green roofs (vegetated or living roofs) and plaza decks. Green roofs and plaza decks are both fundamentally different types of waterproofing, but both require the same criteria to guarantee protection:
- Factory controlled membrane thickness
- Accommodation of building movement
- Performance in ponded water conditions
- Resistance to roots and decay
- Puncture resistance
- Secure seams
- Proven performance history
Friday, August 24, 2007
How to Design a Wind-Resistant Single-Ply Roof System (4 of 4)
The last of four tips from Stan Graveline, VP of technical services at Sika Sarnafil.
Don't forget to secure rooftop equipment. Even the most impeccably designed roof has no chance against a windstorm that sends rooftop mechanical equipment tumbling about. Poorly secured rooftop equipment can cause extensive damage to roof membranes.
“Oftentimes, equipment is simply set on curbs with minimal or no fastening,” says Graveline. “These systems are being held by gravity more than anything.” Don’t forget, the appropriate fixation needs to be specified for rooftop equipment.
High Wind Performance
Don't forget to secure rooftop equipment. Even the most impeccably designed roof has no chance against a windstorm that sends rooftop mechanical equipment tumbling about. Poorly secured rooftop equipment can cause extensive damage to roof membranes.
“Oftentimes, equipment is simply set on curbs with minimal or no fastening,” says Graveline. “These systems are being held by gravity more than anything.” Don’t forget, the appropriate fixation needs to be specified for rooftop equipment.
High Wind Performance
Thursday, August 23, 2007
How to Design a Wind-Resistant Single-Ply Roof System (3 of 4)
Another tip from Stan Graveline, VP at Sika Sarnafil.
Make sure to combat air infiltration from within. For certain building types, the roofing system should be designed to resist pressure from both the exterior and interior. For example, buildings operating at positive internal pressure, such as cleanrooms, highly sensitive labs, and high rises, are susceptible to roof damage caused from the pressure within.The typical remedies for resisting internal pressure include beefing up the roofing system structurally, incorporating an air barrier/vapor retarder at the roof deck level, and sealing joints, transitions, and penetrations throughout the roof deck.
Make sure to combat air infiltration from within. For certain building types, the roofing system should be designed to resist pressure from both the exterior and interior. For example, buildings operating at positive internal pressure, such as cleanrooms, highly sensitive labs, and high rises, are susceptible to roof damage caused from the pressure within.The typical remedies for resisting internal pressure include beefing up the roofing system structurally, incorporating an air barrier/vapor retarder at the roof deck level, and sealing joints, transitions, and penetrations throughout the roof deck.
Wednesday, August 22, 2007
How to Design a Wind-Resistant Single-Ply Roof System (2 of 4)
More for tips from Stan Graveline, VP of technical services at Sika Sarnafil to come.
Know the difference between wind speed and wind pressure. Wind speeds need to be converted to pressures by applying the appropriate coefficients to account for a building's surrounding ground roughness and topography, and the roof's height, shape, and slope.
“People don't understand the difference between wind speed and pressure, so they just specify FM 1-90 as the de facto standard, which means 90 pounds per square foot of uplift resistance,” Graveline says. “This results in roofs that are vastly over-designed for all but hurricane-prone areas, thereby costing the owner many thousands of dollars more without any additional benefit.”
Instead, Graveline says Building Teams should design to comply with the relevant requirements of the building codes. In this case, roof wind uplift designs should be calculated according to the American Society of Civil Engineers Standard 7: Minimum Design Loads for Buildings and Other Structures.
High Wind Projects
Know the difference between wind speed and wind pressure. Wind speeds need to be converted to pressures by applying the appropriate coefficients to account for a building's surrounding ground roughness and topography, and the roof's height, shape, and slope.
“People don't understand the difference between wind speed and pressure, so they just specify FM 1-90 as the de facto standard, which means 90 pounds per square foot of uplift resistance,” Graveline says. “This results in roofs that are vastly over-designed for all but hurricane-prone areas, thereby costing the owner many thousands of dollars more without any additional benefit.”
Instead, Graveline says Building Teams should design to comply with the relevant requirements of the building codes. In this case, roof wind uplift designs should be calculated according to the American Society of Civil Engineers Standard 7: Minimum Design Loads for Buildings and Other Structures.
High Wind Projects
Tuesday, August 21, 2007
How to Design a Wind-Resistant Single-Ply Roof System (1 of 4)
Keep posted for tips from Stan Graveline, VP of technical services at Sika Sarnafil. These tips will help protect your roof from hurricanes and other high wind events.
Wind-resistance starts at the roof edge. The vast majority of wind-related roof damage can be linked to the roof edge. Creating an airtight seal between the wall and roof is the most effective way to prevent wind damage at the edge.
The most basic method is to apply a gasket-type two-sided tape between the flashing membrane and the face of the wall. A continuous metal hook strip or other type of pressure bar is then fastened through the membrane and the gasket to insure a long-term seal. On highly irregular surfaces like metal wall panels, custom filler pieces are required to insure the voids are filled and sealed.
Use of proper fasteners is vitally important. New technologies based on alkaline copper quaternary (ACQ) have been found to be much more corrosive, which can be an issue for both the fasteners and the steel decks the blocking may be anchored to.
Find out about High Wind Roofing Systems here.
Wind-resistance starts at the roof edge. The vast majority of wind-related roof damage can be linked to the roof edge. Creating an airtight seal between the wall and roof is the most effective way to prevent wind damage at the edge.
The most basic method is to apply a gasket-type two-sided tape between the flashing membrane and the face of the wall. A continuous metal hook strip or other type of pressure bar is then fastened through the membrane and the gasket to insure a long-term seal. On highly irregular surfaces like metal wall panels, custom filler pieces are required to insure the voids are filled and sealed.
Use of proper fasteners is vitally important. New technologies based on alkaline copper quaternary (ACQ) have been found to be much more corrosive, which can be an issue for both the fasteners and the steel decks the blocking may be anchored to.
Find out about High Wind Roofing Systems here.
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