4. A building envelope is the physical separator between
the conditioned and unconditioned environment of a
building including the resistance to air, water, heat,
light, and noise.
The building envelope is all of the elements of the
outer shell that maintain a dry, heated, or cooled
indoor environment and facilitate its climate control.
5.
6. Building envelope design is a specialized area of architectural and
engineering practice that draws from all areas of building science and
indoor climate control. The many functions of the building envelope can be
separated into 3 categories:
•Support- (to resist and transfer structural loads)
•Control – (the flow of matter and energy of all types)
•Finish- (to meet human desires on the inside and out of the building)
7.
8. The control function is at the core of good performance,
and in practice focuses in order of importance,
rain control; air control; heat and vapor control.
Water and vapor control is the most fundamental as there are numerous strategies
to this end, namely perfect barriers, drained screens and mass storage systems.
One of the main purposes of a roof is to resist water.
Two broad categories of roofs are flat and pitched.
1. Flat roofs actually slope up to 10-15 degrees but are
built to resist standing water.
2. Pitch roofs are designed to shed, but not resist standing
water which can occur during wind –
driven rains or ice damming.
9.
10. Walls do not get as severe water exposure as roofs but still leak water.
Types of wall systems with regard to water penetration are barriers,
drainage, and surface sealed walls.
• Barrier walls are designed to allow water to be absorbed but not
penetrate the wall and include concrete and some masonry walls.
• Drainage walls allow water that leaks into the wall to drain out such
as cavity walls. Drainage walls may also be ventilated to aid drying
such as pressured equalization wall systems.
Moisture can enter lower levels through the walls or floor.
Basement waterproofing and drainage keep the walls dry and moisture
barrier is needed under the floor
11.
12. Control of air flow is important to ensure indoor air quality, control energy consumption,
and avoid condensation and to provide comfort.
The physical components of the envelope include the
• foundation,
• roof,
• walls,
• doors,
• windows,
• ceiling
• and their related barriers and insulation.
Common measures of the effectiveness of a building envelope ensure physical
protection from weather and climate, indoor air quality and energy efficiency.
13. The thermo envelope, or heat flow control layer, is part of a building envelope
but may be in a different location such as in a ceiling.
The difference can be illustrated by understanding that an insulated
attic floor is the primary thermal control layer between the inside of a building
and the exterior while the entire roof (outside surface) to the interior paint
finishes on the ceiling comprises the building envelope.
This is used to determine temperature differences on the interior and exterior
surfaces which may result in identifying moisture issues from
water intrusion or condensation.
14.
15. Conducting an organized building inspection at least once a
year should be part of every Building Manager’s Operation and Maintenance
Program.
Until a problem is observed, it can’t be fixed. Document
deterioration or water infiltration conditions will allow you to
plan prompt repairs or for minor issues that don’t demand
immediate interventions, to monitor the area over time.
If the problem should escalate, you have documentation
or logs and evaluate how deterioration has progressed.
Regular Inspections are Key to Building Envelope Integrity.
17. Examining building components takes time. With many
obligations vying for attention, why book a day out of your
overscheduled calendar to take camera and clipboard
or smart phone in search of crack?
For good reason. It may seem overly precautious to look
for problems where there seem to be none, but actually
it’s sensible to invest a day or two a year on a building
envelope evaluation
If you spot a puncture, small intrusion, crack in an opening, small
leak, etc. the repair is very minor compared to putting buckets in
place to catch the water intrusion coming into the envelope.
18.
19. Inspect roofs, facades, windows and doors regularly to:
•Identify materials near the end of their service cycle
•Anticipate and plan for replacement
•Catch small problems before they become big ones
•Expand component lifespan
•Avoid unforeseen emergency repairs
•Minimize major capital expenditures
20.
21. Collecting building envelope data on a regular basis
establishes a storehouse of information manufacturers,
warranties, age of components, and the success of ongoing
maintenance practices.
As a preferred partner with Protechs’s Disaster Emergency
Response Program you will have at your request
specialized tools, programs, and information to assist you
in developing a complete history of your building and
grounds.