- 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
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:
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.
Wednesday, August 15, 2007
Seven Tips to Picking a Quality Waterproofing System
When choosing a waterproofing system, there are several factors that should be taken into consideration. The right waterproofing system should:
1. Provide Factory Controlled Membrane Thickness — Sheet waterproofing membranes are manufactured in a controlled environment, eliminating thickness variations found in field-applied systems. Thin spots can lead to a premature failure in the waterproofing system.
2. Accommodate Building Movement— Waterproofing systems need to be flexible enough to withstand structural and thermal movement, and versatile enough to provide design options for each application.
3. Perform in Ponded Water Conditions – Decks will hold water. The waterproofing membrane must withstand ponded water and constant damp conditions.
4. Resistant to Roots and Decay – Roots are very aggressive and can penetrate some types of waterproofing materials. The waterproofing system must be resistant to roots and should not deteriorate in damp environments.
5. Puncture Resistance – Waterproofing membranes must be tough and highly puncture resistant to withstand potential damage during and after installation. Protection layers will provide protection, but there will be times during the construction process when the waterproofing membrane will not be covered.
6. Secure Seams – Sheet membranes are seamed together in the field to form a continuous waterproofing barrier. The seams must be the strongest part of the system, not the weakest.
7. Proven Performance History — Make sure the company behind the waterproofing system has a history of proven performance on projects similar to yours.
Click here to read more about waterproofing systems.
1. Provide Factory Controlled Membrane Thickness — Sheet waterproofing membranes are manufactured in a controlled environment, eliminating thickness variations found in field-applied systems. Thin spots can lead to a premature failure in the waterproofing system.
2. Accommodate Building Movement— Waterproofing systems need to be flexible enough to withstand structural and thermal movement, and versatile enough to provide design options for each application.
3. Perform in Ponded Water Conditions – Decks will hold water. The waterproofing membrane must withstand ponded water and constant damp conditions.
4. Resistant to Roots and Decay – Roots are very aggressive and can penetrate some types of waterproofing materials. The waterproofing system must be resistant to roots and should not deteriorate in damp environments.
5. Puncture Resistance – Waterproofing membranes must be tough and highly puncture resistant to withstand potential damage during and after installation. Protection layers will provide protection, but there will be times during the construction process when the waterproofing membrane will not be covered.
6. Secure Seams – Sheet membranes are seamed together in the field to form a continuous waterproofing barrier. The seams must be the strongest part of the system, not the weakest.
7. Proven Performance History — Make sure the company behind the waterproofing system has a history of proven performance on projects similar to yours.
Click here to read more about waterproofing systems.
Tuesday, August 7, 2007
Former Greenpeace Leader Defends PVC
In the July 16th issue of USA Today it was a reported that electronics companies are trying to remove “nasty chemicals” from their products. In their list of “nasty chemicals” they had made health claims about PVC (polyvinyl chloride) that were pushed by Greenpeace, an international environmental organization.
In a letter to the editor, Dr. Patrick Moore, co-founder and former leader of Greenpeace has condemned the electronic manufacturers for “blindly following the Greenpeace political agenda,” which is “devoid of any scientific basis.” He goes on to point out how PVC is one of the safest and most sustainable materials available.
Keep reading for his full letter to the editor of USA Today.
In a letter to the editor, Dr. Patrick Moore, co-founder and former leader of Greenpeace has condemned the electronic manufacturers for “blindly following the Greenpeace political agenda,” which is “devoid of any scientific basis.” He goes on to point out how PVC is one of the safest and most sustainable materials available.
Keep reading for his full letter to the editor of USA Today.
The reason I left Greenpeace was because of scientifically-baseless campaigns like the one aimed at removing PVC from electronics ("Electronics makers break out 'green' initiatives," July 16).
PVC is one of the most safe, sustainable, flexible and cost-effective materials available. Alternatives are more expensive, less versatile and often pose unknown health or environmental risks.
The most rigorous risk assessment ever undertaken by the European Union on plasticizers used in PVC - conducted over 10 years - concluded that these widely used plasticizers should not be classified as hazardous and pose no risks to either human health or the environment from their current use.
Contrary to the statements of some anti-PVC activists, all types of PVC products can be recycled and reprocessed into second-generation products. More than one billion pounds of PVC are recovered and recycled into useful products in North America annually. Additionally, compared to other materials typically used in computers, PVC is among the lowest in terms of embodied energy and emissions of CO2 in its manufacture. It is therefore one of the most climate-friendly materials.
As for the burning of PVC referenced in your article, if Greenpeace and other activists are truly concerned about dioxin, they should be seeking a ban on wood-burning fireplaces and on- and off-road engines, since those are the single biggest sources of dioxin emissions in the country. By comparison, the vinyl sector contributes about 13 grams - less than 1 percent of the total amount of dioxin generated annually in the United States.
Electronics manufacturers appear to be blindly following the Greenpeace political agenda, an agenda devoid of any scientific basis that will result in more expensive, less climate-friendly products whose
health and environmental risks are unknown.
Subscribe to:
Posts (Atom)
