vr1047 er 1

7/29/2019 vr1047 er 1

1/20

Building Envelope Condition Assessment

for

VAS 1047 - Chelsea Terrace

1040 Pacific Street, Vancouver, British Columbia

Presented to:

Strata Corporation VR 1047

Prepared by:

McCuaig &Associates Engineering Ltd.

File Number: 20110209

Date: September 30, 2011

7/29/2019 vr1047 er 1

2/20

TABLE OF CONTENTS

EXECUTIVE SUMMARY ........................................................................................................... i!SUMMARYOFOBSERVATIONS............................................................................................ I!SUMMARYOFRECOMMENDATIONS ............................................................................... III!

1.0! INTRODUCTION .............................................................................................................. 1!1.1! TERMSOFREFERENCE................................................................................................ 2!1.2! BUILDINGDESCRIPTION&HISTORY....................................................................... 2!

2.0! DOCUMENTS REVIEWED ............................................................................................. 4!3.0! METHODOLOGY ............................................................................................................. 6!4.0! DESCRIPTION OF BUILDING ENVELOPE ASSEMBLIES ...................................... 9!

4.1! ROOFASSEMBLIES....................................................................................................... 9!4.2! BALCONIES,ROOFDECKS,ANDPLAZADECKS.................................................... 9!4.3! PARKINGGARAGE ..................................................................................................... 12!4.4! LIVINGSPACES ........................................................................................................... 13!4.5! WALLS........................................................................................................................... 14!4.6! WINDOWSANDDOORS ............................................................................................. 19!

5.0 ! OBSERVATIONS, DISCUSSIONS, AND RECOMMENDATIONS ......................... 22!5.1! OCCUPANTSURVEY .................................................................................................. 22!5.2! ROOFS............................................................................................................................ 23!5.3! BALCONIES,ROOFDECKS,ANDPLAZADECKS.................................................. 25!5.4! PARKINGGARAGE ..................................................................................................... 30!5.5! INTERIORSPACES....................................................................................................... 33!5.6! WALLS........................................................................................................................... 34!5.7! WINDOWSANDDOORS ............................................................................................. 35!

6.0! FINAL REMARKS........................................................................................................... 38!

List of Tables

!"#$%&'&(&)%*+,,%-."/0+-1&2&34.5%/!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!"""!!"#$%&6&(&7-0/1&89%:%&;-/%:0+:&;-1

7/29/2019 vr1047 er 1

3/20

Building Envelope Condition Assessment for Chelsea Terrace


Page i 09/30/2011

EXECUTIVE SUMMARY

McCuaig and Associates Engineering Ltd. (MAE) was retained by Strata Corporation VR 1047

to complete an investigation of the performance of the building envelope assemblies that Chelsea

Terrance. The building is located at 1040 Pacific Street in Vancouver, British Columbia.

This investigation included an evaluation of parking garage, roofs, balconies, and wall

assemblies as well as an evaluation of interior conditions as they relate to building envelope

performance.

The building, which was constructed in 1981, consists of 112 single-level condominium units.

The roofs are typically low-slope (flat) roofs comprised of 2-ply SBS membrane. Some areas

have pitched metal roofing. The exterior walls are either painted concrete or stucco cladding

over light-gauge steel framing.

Below grade wall assemblies consist of concrete walls with liquid dampproofing applied to the

exterior face.

This investigation consisted of:

Visual inspections of various building envelope components, both exposed and normallyhidden;

A perusal of the buildings original construction drawings; Administration and evaluation of an occupant survey; and; Performing invasive testing from the interior side of select exterior walls.

SUMMARY OF OBSERVATIONS

Roof Assemblies

The main roofs were in relatively good condition and have approximately five years of service

life remaining. The lower roofs were in poorer condition, leaks are occurring, and should be

replaced.

Balconies, Roof Decks, and Plaza Decks

Most of the balconies on the building are protected by the balconies above. It is recommended

that the balcony membranes on the exposed, high-risk areas be replaced. These balconies have

7/29/2019 vr1047 er 1

4/20



Page ii 09/30/2011

little to no overhang to protect them from the elements and are continuously capturing bulk water

during precipitation. Additionally, a new rainwater collection system is recommended to

properly handle the water form the balconies.

It is recommended that the roof decks be further inspected if any roof work is to proceed at

Chelsea Terrance and replace these membranes, if required. The plaza deck membrane appearsto be nearing the end of its service life replacement is recommended over the next three to five

years.

Parking Garage

The walls of the parking garage are allowing some water to infiltrate, but this is not seen as a

structural issue. Various repairs schemes are recommended.

The suspended slab in the parking garage has had some structural damage. The extent of the

damage and the repair options are being dealt with independently from this report. It is

recommended that a traffic coating be installed on the suspended slab to prevent any further

water migration.

Living Spaces

High humidity was noted is some residents suites. The residents can generally manage this

humidity themselves and recommendations are presented in the report.

Exterior WallsExterior walls appear to have provided adequate performance to date. Some water ingress has

been occurring at the base of the wall, which has been attributed to exterior membrane failures.

Exterior sealant (caulking) should be removed and replaced throughout the building.

Windows and Doors

The swing doors at the building are performing as intended. Sliding doors and windows have

reached their life expectancy but still function. New windows and sliding doors are

recommended to increase the efficiency and resident comfort within the building.

Water stains and areas of deteriorated sheathing were observed at several isolated locations in the

vicinity of windows, providing evidence that windows are leaking. The damage is minor and

isolated, therefore it is not cause for immediate concern.

7/29/2019 vr1047 er 1

5/20



Page iii 09/30/2011

Building paper lap details in the vicinity of windows are inconsistent. At some locations, laps

are properly shingled, at some locations laps are reverse shingled, and at some locations gaps

exist between sheets of building paper.

SUMMARY OF RECOMMENDATIONS

Our recommendations, along with order of magnitude budgets to implement our

recommendations, are summarized in Table 1. Unless noted otherwise, implementation of these

recommendations need not be considered urgent, but should be completed within the next five

years.

Table 1 Recommendations & Budget

Ref. Recommendation Budget Time Frame

5.2.r1 Main Roofs The existing membrane should be

expected to provide approximately five more years of

reliable service. The Strata should budget in the

upcoming years to replace the main roofs with a new

SBS roofing system

$ 275,000 5 Years

5.2.r2 Lower Tier Roofs - A roof replacement program for

these smaller roofs should be implemented within the

following year. The roofs membranes should be

replaced with a new SBS system. New rain water

leader design should be incorporated, where required

$ 45,000 As soon as feasible

5.2.r3 All Roof Areas - A qualified tradesman should review

the low-sloped roofs annually and any required

maintenance should be performed during this review.

$ 2,000 Annually

5.3.1.r1 Suite #813 The existing balcony membrane should be

removed and replaced with a new SBS system

including concrete pavers overtop. The corroded steel

framing members must be replaced with new. This

work will entail removing the interior finishes and

stucco and replace with new

$ 15,000 As soon as

Possible

7/29/2019 vr1047 er 1

6/20



Page iv 09/30/2011


5.3.1.r2 Upper Exposed Balconies The existing balcony

membranes should be removed and replaced with a

new SBS system, including concrete pavers overtop, as

soon as feasible for The Strata. The balcony of Suite

#608 should also have the membrane replaced.


5.3.1.r3 Balcony Rain Water Collection System A new rain

water collection system be installed on the balconies

(and roof decks where applicable) that collects the

water, directs it to the ground level, and bypasses all

balconies beneath.


5.3.2.r1 Roof Decks The Strata review the age and condition

of the roof deck membranes and, if warranted, replace

them while other roof work is being completed.


5.3.3.r1 Plaza Deck Membranes The plaza deck membranes

should be removes and replaced with new. This work

could be completed possibly in three phases in the

coming years. It would be prudent to commence this

work in approximately three years time and continue

the remaining two phases one year apart.

$ 75,000

X 3 phases =

$ 225,000

3 to 5 Years

5.4.1.r1 Parking Garage Walls - The Strata should inspect

existing epoxy injection sites annually. Inspectionsshould occur during a prolonged period of wet weather.

If the leakage occurs through existing sites, re-injection

should be considered. If leakage begins to occur at

locations that have not been previously injected The

Strata should consider implementing one of the above

note leakage mitigation schemes.

Dependant on

repair scheme

Annually,

dependant onrepair scheme

5.4.2.r1 Parking Garage Slabs Apply a traffic coating to the

suspended slabs in the parking garage to prevent future

water migration through the slab and subsequent

concrete decay.


7/29/2019 vr1047 er 1

7/20



Page v 09/30/2011


5.5.r1 Interior Spaces The Strata should review the

operation of the kitchen and bath exhaust fans in the

suite to ensure they are performing as intended. Any

non-operational fans should be replaced. The Strata

should also advise all the residents that humidly levelswithin their suite should be managed by opening

windows and the use of exhaust fans.

Negligible As soon as

possible

5.6.r1 Exterior Walls The exterior sealant be removed and

replaced with new and all exterior locations. This

should include all window/door interfaces, cladding

interfaces and flashing details.

$ 50,000 2 Years

5.7.r1 Windows and Doors If The Strata were looking to

upgrade the performance of the windows, newlymanufactured windows would provide substantial gains

with regards to energy savings and resident comfort.

This upgrade would also eliminate the majority of the

condensation issues with the windows.

$ 400,000 At The Stratas

discretion

5.7.r2 Entire Building Envelope The building envelope

should be investigated at regular intervals and a regular

maintenance program should be established.

$ 12,000 5 Years

7/29/2019 vr1047 er 1

8/20



Page 1 09/30/2011

1.0 INTRODUCTION

McCuaig & Associates Engineering Limited (MAE) was retained by Strata Corporation VR

1047 (The Strata) to conduct an evaluation of the building envelope assemblies that enclose the

building located 1040 Pacific Street in Vancouver, BC. This building is known as Chelsea

Terrace. Documentation that we have received indicates that the building was constructed in1981.

This report has been organized into a number of sections and appendices. A description of the

subject matter of each section and appendix is presented below. Section titles are indicated in

bold uppercase font.

The INTRODUCTION provides an overview of the investigation including terms of reference

and a description of the development.

The DOCUMENTS REVIEWED section describes the original construction drawings that

were made available to MAE for this investigation. Relevant information that was obtained from

the drawings is also described.

The methods and tools that were used to conduct this investigation are described in the

METHODOLOGY section of the report.

The section entitled DESCRIPTION OF BUILDING ENVELOPE ASSEMBLIES describes

the relevant building envelope assemblies that enclose the buildings that make up the building.

In the OBSERVATIONS, DISCUSSIONS AND RECOMMENDATIONS section, our field

observations are described and their relevance to the performance of the building envelope is

discussed. Photos that illustrate many of our observations are also contained in this section.

Where applicable, recommendations to correct observed deficiencies are also discussed in this

section. Order of magnitude budgets are also presented for each of the recommendations.

Our concluding remarks, including the limitations of this investigation are contained in the

section entitled FINAL REMARKS.

Drawings of the various building elevations are presented in APPENDIX A. The locations

where exploratory openings were conducted are shown on these drawings along with other

relevant comments.

7/29/2019 vr1047 er 1

9/20



Page 2 09/30/2011

APPENDIX B contains a Glossary of Terms referred to throughout this report.

APPENDIX C contains the completed occupant surveys.

1.1 TERMS OF REFERENCE

Briefly, this investigation concerns previous, ongoing, or potential water ingress issues that are

related to the following building envelope assemblies:

Roofs; Balcony structures; Plaza decks; Exterior walls below, at, and above grade, and; Exterior windows and doors.The terms of the Client/Engineer agreement specify that upon completion of our field

evaluations we must prepare a written report that:

Describes our observations; Provides recommendations to rectify observed building envelope deficiencies; and; Provides an estimate of order of magnitude costs to implement our recommendations.

1.2 BUILDING DESCRIPTION & HISTORYChelsea Terrace has been constructed in a high-density residential neighborhood on a sloping lot.

The development is surrounded by mid and high-rise residential buildings and is approximately

one block north of the ocean. The building consists of 118 units plus one amenities room and a

common laundry room.

The building is nine stories high with parking on the first floor and a portion of the second floor.

Residential units start on the second floor and extend to the top floor. All units have access to

either private patios or balconies off their suites. Each unit is heated with individual electric

baseboard heating systems.

The building structure is constructed from cast-in-place concrete. This concrete makes up the

structural wall and floor components of the building as well as a large portion of the exterior

cladding. At some locations the exterior walls are comprised of light-gauge steel stud framing

7/29/2019 vr1047 er 1

10/20



Page 3 09/30/2011

with exterior sheathing and stucco as the exterior cladding. The windows and sliding doors in

the building have double glazing and date back to the original construction.

The majority of the roofs at Chelsea Terrace are low-slope roofs, commonly referred to as flat

roofs, and are protected with a 2-ply SBS sheet membrane. Pitched metal roofing exists at

some location on the building. The low-sloped roofs direct water into internal drains while the

pitched roofs direct water into external gutters and rain water leaders.

Detailed descriptions of roof and wall assemblies are found in Section 4.0.

7/29/2019 vr1047 er 1

11/20



Page 4 09/30/2011

2.0 DOCUMENTS REVIEWED

The Strata gave MAE permission to purchase copies of the original construction drawings from

the City of Vancouver. The drawings that were reviewed and are relevant to this report are

described below:

Architectural Drawings:

Consultant: Hale Architects

Latest Issue Date: December, 1979

Purpose of Issue: Proposal to Municipality

Drawings Provided: A1 to A24

Structural Drawings:

Consultant: Read Jones Christoffersen Ltd.

Latest Issue Date: November, 1979

Purpose of Issue: Issued for Building Permit

Drawings Provided: S8 and S9 (other structural drawings were not available)

For the remainder of this report, the term Construction Drawings shall refer to Drawings A1 to

A24, S8, and S9, as described above. It should be noted that the Construction Drawings were

received in a compressed (smaller size) format and, due to their age, are at times difficult to read.

The structural drawings were incomplete and difficult to read, thus only minimal information

pertaining to the buildings structural systems was available. MAE acquired additional drawings

of the building including; Plumbing, Mechanical, and Sprinkler drawings but these were not

relevant for this investigation. All the drawings listed above will be handed over to The Strata

for their records when the investigation is complete.

The Construction Drawings show:

A site plan; Small scale floor plans including dimensions;

7/29/2019 vr1047 er 1

12/20



Page 5 09/30/2011

Building elevations, including a list of exterior finishes; Selected building sections, including dimensions, and; Window and door schedules.The Construction Drawings are also referenced to provide orientation for the project and to

develop preliminary budgets for repairs or remedial work.

7/29/2019 vr1047 er 1

13/20



Page 6 09/30/2011

3.0 METHODOLOGY

This section describes how this investigation was conducted.

1. Prior to our site work, an online occupant survey requesting information about knownbuilding envelope issues administered. Some residents, in lieu of the online version,submitted hard copies of the surveys. Copies of the completed surveys can be found in

Appendix C.

2. The Construction Drawings were reviewed in order to become familiar with the project.3. Subsequent to reviewing the drawings, visual non-invasive inspections of exposed structural

components were completed. The purpose of the inspections was to evaluate the condition of

the exposed structural components that must provide acceptable service levels for the

remaining life of the building.

4. Visual inspections of randomly selected building envelope components that are normallyexposed to view were conducted. This included inspections of various roofs, balconies, plaza

decks, and the exterior face of wall and window assemblies.

5. Interior conditions within selected units were evaluated. Inspections of interior conditionsfor indications of water ingress from the exterior or excessive condensation, along with

evidence of broken seals between inner and outer glazing, were conducted.

6. Selected building envelope components that are normally hidden were visually inspected.The selected areas were dictated by the results given in the occupant surveys and our past

experience with similar buildings. The inspections were accomplished by removing sections

of drywall from the interior of the walls and creating an exploratory opening to view the

insulation, steel studs, and wall sheathing within the assembly.

Specific units that were inspected are listed in Table 2. For each unit listed in Table 2,

interior surfaces of exterior walls and windows were inspected and humidity levels were

checked.

7/29/2019 vr1047 er 1

14/20



Page 7 09/30/2011

Table 2 Units Where Interior Inspections Occurred

Unit Areas Inspected

204: Exterior wall, skylight, and sliding door area. No exploratory

openings were conducted.

306: Exterior wall, bedroom wall, and sliding door area. An

exploratory opening was conducted.

308: Exterior walls, bedroom walls, and sliding door area. Four

exploratory openings were conducted.

511: Soffit and sliding door area. No exploratory openings were

conducted.

608: Soffit, balcony, and sliding door area. No exploratory openings

were conducted

810: Exterior wall in living room. An exploratory opening was

conducted.

813: Exterior walls and sliding door area. The drywall was previously

opened up in this area.

Interior suite inspections were completed on August 29th, 2011. Exterior inspections took place

on both August 29th and 30th, 2011. The parking garage was reviewed at various times during

the week of August 29th, 2011. It was generally sunny and warm on the days immediately prior

to the inspection days.

Relevant weather data is presented in Table 3. The weather data was obtained from the

Environment Canada Website. The weather data pertains to the weather station located at the

Vancouver International Airport, which is the closest weather station to the building that

provides reasonable historical precipitation data.

7/29/2019 vr1047 er 1

15/20



Page 8 09/30/2011

Table 3 Inspection Schedule And Weather Data

DatePrecipitation at the

Vancouver AirportHistorical Data

29 Aug 11 0.0.mm

30 Aug 11 0.0 mm

In the 60 days prior to August 29,

2011, a total of 57.2 mm of rain fell on

10 days. This is slightly less the

historical average (1971-2000) of 78.7

mm for the same period (July and

August).

A review of Table 3 indicates that the precipitation that preceded our fieldwork was

approximately average. This suggests that the invasive inspections occurred at a time when the

building envelope underwent a reasonable test of its performance in the summer months.

7/29/2019 vr1047 er 1

16/20



Page 9 09/30/2011

4.0 DESCRIPTION OF BUILDING ENVELOPE ASSEMBLIES

Descriptions of the various building envelope assemblies that are the subject of this report are

provided in this section. The descriptions are based on The Construction Drawings, our

experience with similar buildings and, in some instances, our invasive visual inspections. There

has been no attempt to verify the presence of all of the components described herein.

4.1 ROOF ASSEMBLIES

The majority of the roofs at Chelsea Terrace are low-slope and are protected with 2-ply SBS

membranes. There are three small pitched metal roof assemblies on the east on northeast sections

of the building, one of which has been replaced in the past two years. The pitched metal roofs

drain by allowing water to flow from their peaks to external gutters at the perimeter of the roof.

Due to the lack of drawings, we are unable to confirm the presence and the location of all the

pitched roof components. The low-sloped roofs handle bulk water through interior drains. Thissection will deal primarily with low-sloped roofing.

The low-sloped roofs are present over the main upper roof area, the mechanical room, the lower

tiered roofs, and some smaller projections on the north and south elevations. These roofs have

SBS sheet membrane installed as the waterproofing layer. A good quality SBS roof membrane

that has been properly installed can be expected to provide approximately 20 years of reliable

service. Multiple penetrations exist through the membrane including plumbing stacks, exhaust

vents, turbine vents, and surface drains.

The SBS membrane is typically applied with two layers; the base sheet is normally mechanically

fastened to the structure and the cap sheet is torched-on and fully adhered. The cap sheet is

granulated for UV light resistance. It appears that this membrane has been installed directly to

the concrete substrate and most likely has a protection board or fibre board between the

membrane and concrete.

4.2 BALCONIES, ROOF DECKS, AND PLAZA DECKS

Roof decks are outdoor living spaces that are situated over living spaces. Balconies are outdoor

spaces connected to the suites that are not over living spaces. Plaza decks are pedestrian access

deck areas that are typically overtop of parking areas. Chelsea Terrace has balconies, roof decks,

and plaza decks all structurally supported by cast-in-place concrete.

7/29/2019 vr1047 er 1

17/20



Page 10 09/30/2011

4.2.1 Balconies

The drawings indicate that water ingress through the balconies is prevented by a liquid

membrane applied to the cast-in-place concrete; a concrete topping was placed overtop. The

balconies are serviced by internal drains, which direct water to the balcony floors directly below.

The soffit area on the underside of the balconies has a strip vent to provide ventilation to the

soffit cavity.

In accordance with good water management practices, the balcony floors are generally sloped

away from the building. It is our understanding that the balcony membranes have not been

replaced at the building, although some balconies have received isolated repairs.

The floor layout at Chelsea Terrace is such that most balconies are situated beneath the balconies

above. Refer to Photo 1. This layout provides substantial protection from precipitation and wind

driven rain. The upper level balconies are not protected with such a generous overhang and are

more vulnerable. Rain water freely accumulates on these upper balconies and must be collected

by the surface drain.

.

Photo 1 Typical balcony layout.

Aluminum and glass guardrails provide balcony fall protection. The guardrails are fastened to

the balcony upstand wall framing and into the exterior walls. The fastener holes through the

building exterior provide a water ingress point.

4.2.2 Roof Decks

The roof decks are typically located on the uppermost levels and are far fewer than the number

of balconies on the building. The drawings indicate that water ingress through roof decks is also

7/29/2019 vr1047 er 1

18/20



Page 11 09/30/2011

prevented by a liquid membrane, with a concrete topping placed overtop. During the site

investigation it was noted that some roof decks have had repairs completed, which most likely

involved a membrane replacement and concrete pavers installed overtop. Refer to Photo 2.

.

Photo 2 Roof deck on northeast corner of the building.

The roof decks are also serviced by internal drains, which either direct water to the balconies

directly below or the to the internal plumbing system. The guardrails match the design of the

balcony guardrails.

4.2.2 Plaza Decks

The plaza decks are located on thesecond and third levels and are either

over living space or the parking garage.

It appears that the plaza deck assembly

has been updated from the original

construction, but it still appears to be

aged. Concrete pavers have been

placed over drainage matt, which sits

atop a liquid applied membrane. Refer

to Photo 3. On the west side of thebuilding, landscaping has been installed

overtop of the plaza deck membrane..

Photo 3 Plaza deck area on the south side of the building.

7/29/2019 vr1047 er 1

19/20



Page 12 09/30/2011

The plaza decks are typically integrated into the exterior walls to provide the base wall

waterproofing. Bulk water is directed to internal by-level drains. These drains are connected to

the buildings plumbing system.

4.3 PARKING GARAGE

The parking structure is located on the first and second levels of the building. The first level

consists of a concrete slab-on-grade while the second level is a suspended concrete slab. It does

not appear that the parking slabs have been protected with a traffic coating to prevent water

migration through the slabs. The exterior ramp accessing the parking garage does have a

waterproof traffic coating, which has been installed in the past year.

The exposed structural components within the parking garage were reviewed during the

investigation. The structural components that were inspected included:

The top surfaces of the level 1 and level 2 slabs; Portions of the underside of the level 3 slab which are visible from level 2. Note that the

underside of some portions of the level 3 slab are covered with insulation.

The underside of the suspended portions of the level 2 slab, which are visible from level 1.The majority of the structural components that support this building have been constructed from

concrete. Typically, structural concrete is reinforced with embedded steel rods (rebar). It

appears that level 3 and the majority of the upper parking garage floor (level 2) are supported bystandard reinforced concrete slabs. The northeast quadrant of the level 2 floor and the level 1

floor consist of concrete slabs that are supported by the underlying soil henceforth referred to

as slabs on grade. It is likely that the slabs on grade are either un-reinforced or lightly

reinforced.

When a concrete structure is loaded it deforms and becomes stressed. Certain components of the

concrete stresses are transferred to the rebar, which often causes cracks to occur in the concrete.

These cracks, which are necessary to transfer stresses from the concrete to the rebar, are not

generally a cause for concern, unless they allow water to pass through the structure.

If water is allowed to continually pass through a section of concrete it will increase the likelihood

that rebar or other embedded metal components will corrode. The corrosion process causes the

steel to expand and exert outward pressure on the surrounding concrete. Eventually, the outward

pressure will cause the concrete to delaminate and spall away. If corrosion occurs in several

7/29/2019 vr1047 er 1

20/20



P 13 09/30/2011

adjacent bars and if it is severe enough the structures load carrying capacity will be reduced.

Corroded rebar that has been installed purely for crack control will not significantly reduce the

slabs load carrying capacity, however, the incidence of corroded crack control steel may also

indicate the presence of corroded main steel. It may take several years of water ingress before

the level of corrosion is severe enough to become a structural concern.

Other consequences of ongoing water ingress through concrete include:

The appearance of rust stains, which often indicate that the corrosion process has started; The appearance of efflorescence, which is a milky liquid that forms when water mixes with

the lime in the concrete. The appearance of efflorescence is not detrimental to the concrete,

however if it comes into contact with vehicles, it can damage their finish.

4.4 LIVING SPACES

Water vapour is generated inside living spaces by activities such as bathing, cooking, and

breathing. Warm air can hold more water vapour than cold air. When warm air that is laden

with water vapour comes into contact with a cold surface, for example a cold aluminum window

frame, the air cools. When the air cools, it can no longer hold as much vapour, causing the

vapour to transform to a liquid state. Liquid water then forms against the cold surface. This

process is referred to as condensation. Condensation generally increases when:

The number of residents within each unit increases; The resident keeps multiple indoor plants; Windows and doors are inadequately designed to resist heat flow between interior and

exterior spaces;

There is an inadequate supply of fresh air.Condensation can be controlled by:

Eliminating cold interior surfaces; During cold weather, exchanging relatively dry exterior air for relatively moist interior air.

This can be achieved by ensuring that each unit is adequately ventilated. Suitably designed

exhaust fans, open windows, or a combination of the two can provide adequate ventilation.

vr1047 er 1

Documents

Transcript of vr1047 er 1