An External Wall Construction through the Application of Brick Veneer - Term Paper Example

Table of contents A REPORT ON EXTERNAL WALL CONSTRUCTION VENEER BRICK Abstract Building and construction are rapidly growing following the rise in demand of these premises ranging from residential to commercial premises. Safety in these premises is the core function undertaken by the Building Construction Authority (BCA) since irregularities through failure by unscrupulous and dishonest constructors to follow the laid down quality benchmarks can be very disastrous for the humankind as well as a massive loss of property that hurts the economy of nations. The paper aims at reporting the earlier findings on a close examination of an external wall construction through the application of brick veneer. To help properly unearth this, a close examination through research was carried and obtained data were analyzed and cross-checked against the set rules by the BCA. Questionnaires were issued to the said construction company and the respondents were analyzed Areas underscored by the constructor were thumped up and areas of variation attracted the necessary recommendation as the safety and fear of loss of property were the core bench-marking areas upon which the research was pegged. Introduction In every building society, dishonesty amongst the premises owners as well as the construction companies winning such tenders is inevitable. The BCA in an attempt to scale this daunting challenge to minimal impacts levels has come up with the quality standards to be strictly adhered so as a way of guarantee of safety to people, as well as the property. Despite this effort, close examination of buildings shows failure to meet these set standards as corruption has enabled such unworthy dwellings to continue existing. This has hence led to serious damages resulting from massive destructions of property and the extreme, loss of lives. The paper seeks to shed more light by a keen examination of an on-course external wall construction and counter check whether such standards are applied. A further recommendation based on the analysis of such information will aid in ensuring that the dwellings remain safe for residents as well as the properties in order to eliminate externalities resulting from the collapse of such premises. Body Methodology The paper appreciates the need to unearth this scenario and subsequently the researcher did a thorough probing of the constructor as well as his team via the use of questionnaires as well as the oral interview. The results that were obtained were encoded. Tie connection tests and brick Veneer walls panel were carried out to access the impacts of various connection procedures on the wall system performances. The research was conducted on one of the buildings under constructions that were located on higher seismic prone area as well as one kilometer from the salty water body. Several tests were done to ascertain the stiffness and strengths of such wall to resists loads that are subjected to them through such catastrophic natural occurrences like earthquakes. In addition, several cross-checks of the material used and the installation including the proportion and the types of motor were conducted. Results and Analysis Type of motor used The site of the building determines the kind of   required motor to be used. Proximity to the salty water bodies also determines the kind of the motor to be used. The AS3700 requires that where one is building at a distance of 1KM away from the water, to which the construction under research is a party, M2 type of motor should be used. This was not met as per the results of the research thus violating the standard. The following table shows the types of motors. Motor type table The table indicates the types of possible combination requirement of the motor. The AS3700 requires that the cement should comply with the AS3972 or AS1316 and that the lime to be in line with rule 1672.1. The sand requirement should be free from the deleterious substances which are prone to reduction of the durability of the buildings as they reduce the strength, for instance the sand should not contain detergents as well as fire clay. The water thickener should be very minimal since it is a threat to motor strength. Tie connection The tie construction uses the nail tie which is characterized by reduced strengths that the screw ties but the stiffness is found to be the same for either of the two, analysis reveals that the nail ties should not be used as they fall short of the minimum installation standards as outlined by the BCA. Veneer material Thick limestone panels, 4” thick precast concrete panel with granite Veneer, and standard size clay veneer with 2” air pace 5/8” thick Densglas sheathing on 6” metal at 16” O.C with R19 fiberglass batt insulation. Application of the Weepholes They did not meet the standard requirements as they were spaced at 1500mm against the normal practice of being below the 1200mm requirement and could not properly shed the blown water from the cavities. The emptiness recommendation of Weepholes pegged at 10mm wide was also not followed as they used 20mm hence enabled the insects to enter the cavity. Window and door installation Labeling This is achieved as they are well positioned hence viewing them at a glance or in situ is in compliance with a set standard. To add on this, the required marks on the frames such as housing entails window rating as well as water penetration resistance and also producers’ identification marks. Window installation It is found that windows are properly installed taking all the necessary pre and post installation requirements. Head flashing The stoppage of water from wetting the inner skin has been achieved as the installation has bridged across the window in accordance with the BCA set rules as the ventilation ducts as well as exhaust ventilation projecting horizontally at 150mm on both sides through the opening. Sill flashing Wetting of the inner skin has been prevented as water does not enter the underside of the window. Sill flashing has stopped blown water across the cavity under the window. A minimum projection of the 150mm is met as well as the regulation AS2904. Discussion Treatment of sills The contractor has met the minimum requirement as outlined by the BCA that all the plates in contact with the concrete be pressure treated. The report reveals that these normal practices were met as revealed in the analysis of the data collected. The HUD requirements further expound on this by invalidating sill pressure treatment only as its penetration is estimated to be merely three percent of the wood leaving some other wood parts vulnerable to termite infestation. A further one year warranty is required and use of borate treatment that penetrates deeper and have a durable protection. A requirement is further raised that once some parts of the wood are drilled or cut, further treatment apart from pressure treatment is applicable as these open parts may make the termite find its way through and cause serious damages. Lintels It is affected by rusting and hence degrades its functionality with the time. The BCA requirement standard is the organic zinc coating with silicate coating of 75um thickness. The paper identified that this basic requirement treatment was fully in line with the 2011 BCA requirements and hence the dwelling safety. Window The required standard is met as the overlap on sill flashing has extended the full depth of the sill flashing and hence water entering between the window jambs as the outer skin is drained to fill flashing. Doors opening Care was taken to seal all the openings which are found to provide unnecessary sound insulation hence reducing the wall RW. The researcher found that special heavy weight doors were fitted to eliminate this problem by having an absorbent lined with airspace separating two doors. An acoustic sealant was used to seal openings as these pose threats to reduction of the wall’s RW as they conduct airborne sounds. Expansion/ control joints There is a compliance with regulation that requires that no motor should be used to bridge the control joints. The constructor ensured cleaning of these joints was done after the bricks were laid hence minimizing the possibility of forces transfer to the closing joints hence minimizing the possibility of crack establishment. The highly compressed sheet requirement in the construction of these joints was also achieved and hence dirt and moisture were eliminated from entering the cavity. To the outside, aesthetic treatment was made possible via the use of a compressible caulking material that blended well with motor’s color. Care was taken to ensure elimination of the incompressible caulking compound which poses a threat to bricks. Flashings The constructor was in line with the requirement and sandwiched the flashings and the DPCs between the motors. The research realized that, on the lower course of the bricks was a direct layer of flashings and DPC with the motor being placed on top. The explanation to this is seen to be more practical practice and superior way of treating the flashings. The combination of the flashing and DPC at a length of 150mm requirement was made possible and sealed together. A termite shield was also used as a precaution was also taken to ensure the compatibility of the DPC and the termite shield at the similar joint. To validate the use of DPC, it was laid across the wall and allowed to protrude through the motor and its visibility was ensured on either side after the completion of laying and the subsequent cleaning. This was superior as recessing the flashing underneath the motor would be disastrous as it hinders the shredding of the water that soaks leading to corrosion of the wall. Finish against eaves The researcher identified finishes against eaves were done as per the requirement as the shingles were fully protected hindering any possible damages. Gutters were properly fixed to prevent the penetration of the rain water which further prevented the emergence of cracks that are disastrous and hence the roof was at the best position to protect the dwelling. Gables The requirement was not met as outlined by the BCA as its ends were much exposed to wind and this would have negative effects during the strong winds. This resulted to a flatter roof which facilitates the peeling of gables as it is required that such roofs be steeper with a fixed vertical fin. Variances Light weight panels Light weight panels above the doors that had a weighted sound reduction index, RW less than the wall requirement and have a negative impact hence violating the BCA standards. Appliances Appliances were kept close to the structure and this does not conform to the quality standard as outlined by the authority as these are prone to production of sounds that are unnecessary near such structures. Weepholes Weepholes did not meet the standard requirements as they were spaced at 1500mm against the normal practice of being below the 1200mm requirement and could not properly shed the blown water from the cavities. The perimeter required of 10mm wide for Weepholes was also not followed as they used 20mm hence enabled the insects to enter the cavity. The location being a higher wind area, it is recommended that the narrower Weepholes be used as they are continuously required to remain opened to shed out the blown water into the cavities. A further recommendation is to ensure that any coating applied in the joint be eliminated. Wrong motor type used The 2001 AS3700 requirement of the use of the M2 type of motor in areas that are a kilometer away from the salty water bodies was not applied as the constructor used the M3 type which was in a total violation of the requirement as stated in the AS3700. Gable treatment This has not been given a proper treatment as required by the law. The flatness of the roof is seen to be promoting the effects of the wind. This is posing a serious challenge in such dwellings. This is seen in most cases to be peeled off during strong winds. There is the need to add the vertical fin so that the effects of winds can be minimized as the gable ends are prone to wind. Recommendation Horizontal joint reinforcement This was not done in this case despite the location code requirement since the location was a higher risk seismic zone. The researcher recommends that this be applied without which the building will be very vulnerable to winds and other agents that pose major threats to the future loss of lives as well as massive destruction of valuable properties. Ring and screw-shank nail This should be used in ties connection as this will eliminate the possible nail pull out which has greatly led to massive loss of properties as well as lives. Weepholes failure The standard requirements were not met as they were spaced at 1500mm against the normal practice of being below the 1200mm requirement and could not properly shed the blown water from the cavities. The perimeter should be 10mm wide which was violated as they used 20mm hence enabled the insects to enter the cavity. The location being a higher wind, it is recommended that the narrower Weepholes be used as they are continuously required to remain opened to she out the blown water into the cavities. A further recommendation is to ensure that any coating applied in the joint to be eliminated. Wall tie corrosion In many occasions, wall tie corrosion has led to massive destruction of property as well as loss of lives. The constructors should take a keen consideration. Many parts of buildings have collapsed due to water penetration into the walls. These results from the Veneer distress resulting mainly from the failure of the wall ties. Minimization of the possibility of mortar joint cracks should be conducted to prevent future loss of lives and property. Cracking of walls results from moisture and thermal expansion of bricks interface. More care should be taken to bar water penetration at the corner units as corrosion is rapid when water penetrates the motor joints at the corners closer to the veneer surfaces. Repeated water penetration makes the building to be more vulnerable to destructive agents to the extent that even a mere wind can lead to the collapsing of the wall. Some may argue that it has the least effect as it takes quite a long time to happen but ultimately it puts a major threat and greater destruction when it validates. Evidence at hand suggests that such corrosions are very difficult to identify with the naked eye and it calls for frequent inspections of such causes in order to prevent any unforeseen occurrence. A close examination of the tie thickness, eccentricity at connection to the stud, embedment length on the strength and Veneer stiffness of tie connection as well as tie thickness also varied with the standard as outlined in the BCA. The use of electrical outlets and service pipes it was not avoided and the paper commends an active sealing and the introduction of discontinuity in pipe works as fitting is done. This can be achieved by the use of acoustically rated boxes for all the electrical outlets as well as service pipes. Acoustic sealant should be applied on the sides of the electrical boxes and circumference of all the penetrations. Offsetting the power outlets should be done on either sides of the wall by a minimum length of 100mm. Appliances Appliances those are associated with noise production including but to mention a few water closets, water storage tanks dishwashers to be kept away from the structure with flexible and resilient mounting service and connections. Conclusion BCA outlines the minimum standards that each housing constructor is expected to strictly follow. This is aimed at preventing wall collapse of buildings by being kept at minimum levels as such occurrences have in the past led to massive loss of lives and destruction of property. The researcher has identified the areas that were in line with the set standards as well as those that were in violation. Consequently recommendations have been raised that if adopted will ensure that external wall veneer bricks construction provide safe dwellings that are not prone to collapse due to winds and earthquakes which have remained the common agents putting much threats on lives and the loss of property. References Carpenter, W. J. (1997). Learning by building: Design and construction in architectural education. New York: Van Nostrand Reinhold. Read More