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HomeMy WebLinkAbout05022002 BSC Agenda Item 6 • • • City of West University Place Residential Engineering Requirements General Requirements Any Registered Professional Engineer Licensed by the State of Texas as a Structural Engineer shall be allowed to register with the City of West University Place to do Engineering work in the City provided a prior registration has not been revoked for reasons listed in the section Revocation of Registration below. At the time of registration an engineer must provide proof of current registration, proof of general liability insurance, and sign a statement acknowledging that he has read and understands the specific requirements of the City of West University Place regarding engineering related to residential structures. All Plans submitted for new construction of residences or remodeling of residences where the costs of the remodeling will be in excess of $100,000 and which will require structural modifications to the residence shall be reviewed and approved by an engineer registered with the City of West University Place. Specific Requirements Engineers shall provide a load analysis for the structure. This analysis shall show the loads from the roof through the supporting foundation of any structure. For analysis purposes minimum gravity loads sshall be as follows: l lClaa VV GlU lvaav vv�. Roof: DL=10psf Ceilings: DL=5psf Floors: DL=10psf LL=20psf LL=10psf LL=40psf Wind Loads shall be calculated for the following minimum conditions: Wind Speed: 90mph Importance factor: 1 Exposure: B The engineering firm which designed the structure shall visit the site and inspect the work during construction to confirm that the work is done in accordance with the plans provided. The general contractor's employees or subcontractors shall not perform this function for the engineer. At a minimum the engineer shall inspect the work done on site during the construction of any piers or footings and during the construction of any beams or slabs. At a minimum the engineer shall confirm the following: - That the number and placement of any piers or other footings is correct or acceptable given conditions encountered on site. - That the size and depth of any piers or other footings is correct or acceptable given conditions encountered on site. -That any under reams are of the proper diameter and are free from any debris or caving. • • -that any steel placed in the foundation is of the proper size and is located appropriately and that it has sufficient support to prevent it from moving inappropriately when concrete is placed in the forms. -That any concrete beams are of the proper width and depth and that the forms for such beams are clear of any debris or caving. -That any slab is of the appropriate thickness. -That the weather conditions are appropriate for the placement of any concrete. The engineer shall arrange to meet a City inspector on site to during his inspections or provide other independent verification of his site visits. When the engineer is satisfied that any foundation work has been completed in accordance with the design provided a letter to that effect shall be provided to the City of West University Place. Independent Review The City of West University Place should contract with at least two registered professional engineers to review structural plans submitted for permitting. The scope of this review should be to review the load analysis and basic design for reasonableness. If the reviewing engineer has any questions regarding the reasonableness or completeness of the load analysis or of the structural design he should either contact the design engineer directly to resolve any questions or reject the plans with a list of questions. The Development Services department would then contact the design engineer to resolve any questions. If it is the opinion of the reviewing engineer that the design engineer has not displayed basic competence or due diligence he should advise the City of West University appropriately. Revocation of Registration If a reviewing engineer advises the City that he does not believe a design engineer has displayed basic competence or due diligence of if a design engineer fails to comply with the Specific Requirements above, the design engineer should be given the option of paying a fine of$500 or having his registration revoked. A second offence should result in a $1,000 fine or revocation of registration. A third offence would result in a three year revocation of registration. r 1 S • . 1., City of West University Place•Texas Memo To: Michael Ross Assistant City Manager/Director of Public Works From: Dennis Mack, Chief Building Official eAA- Date: April 15,2001 Re: Foundations The Building Standards Commission is of the opinion the city has experienced excessive failure of residential foundations due to improper designs by Professional Engineers.As a result of this belief they have made a request that the city council discuss the possibility of requiring the city to hire a consulting engineer to review the engineering of foundation plans submitted for permits. It is my opinion the city should not proceed with this proposal for the following reasons. 1. The belief the city has experienced excessive foundation failure due to improper designs by professional engineers is not backed by any methodical study by a Forensic engineer but was simply a conclusion reached by counting the number of foundation repair permits issued by the city in a one or two year period. There was no attempt to establish the cause of foundation failure within the city,nor was their any attempt to authenticate the number of repair permits constituted an excessive percentage of foundation failures for this region of the state.The City of West University Place as well as the surrounding communities is largely made up of areas with clayey soils that shrink and swell with changes in soil moisture content. This shrinking and swelling may cause movement of residential foundations that adversely affects the residence. Other factors may influence foundation performance as well.Some of these factors are inadequate construction,the degree of compaction of the supporting soils,landscaping practices, leaking plumbing, and drainage slope instability. 2. Addressing the cause or causes of foundation movement may preclude the need for structural repairs or reduce the risk of continuing foundation movement after structural repairs. Implementing non-structural recommendations and monitoring foundation performance prior to implementing structural repairs may be a prudent approach,provided it is cost effective and the owner is willing to allow time to foundations.doc measureeeffects of such measures. Some of these n• on-structural remedial measures are as follows: a. Vegetation Alteration. Trees or large shrubs near the foundation cause or could potentially cause soil shrinkage under the foundation. Removal of these trees or shrubs may prevent soil shrinkage and may even result in at least partial restoration of settled areas of the foundation. Removal may, however,result in foundation upheaval due to soil moisture increase or settlement due to root decay. If the trees and shrubs pre-date the structure, pruning of tree branches may be a more prudent approach. b. Root Barriers. If pruning tree roots is not either effective or practical, a root barrier can often mitigate the effects of the tree(s)by limiting root growth under the foundation. Root barriers generally consist of a vertical barrier of low grade concrete,Plexiglas, sheet metal, chemically treated geo-fabric or other appropriate material. c. Gutters and Downspouts. The absence of roof guttering around a structure can cause both erosion and the ponding of water near the structure. If either of these conditions is present, the addition of gutters and downspouts should be installed. Downspouts should be of adequate size to drain roof runoff during typical storms. Extending downspouts at least 5 feet past the edge of the foundation and past the edge of all planting beds is recommended. d. Drainage Improvements. Since foundation movement in expansive soils is related to soil moisture content,it is important to maintain positive drainage away from the foundation to reduce the risk of foundation upheaval. Drainage improvements are appropriate both to address existing upward foundation movement and as preventative measures. e. Surface Grading. Performance based surface grading should be followed that insure the generally desired flow direction is maintained and the requirement that water ponding near the foundation be followed.A minimum slope of 5% (e.g. 5 feet in 100 feet)away from the foundation for at least 5 feet and 2% (e.g. 2 feet in 100 feet) along any swale is recommended. f. Erosion Control. Added soil should have adequate clay content to minimize water movement through the added soil. Retaining structures of significant height should be designed using appropriate soil and structural parameters. The slope should not exceed 15%to minimize erosion yet provide drainage. g. Surface Water Drainage Systems. When inadequate slope exists to provide surface drainage by grading alone, underground drainage systems should be installed. These systems typically consist of one or more • Page 2 dreage inlets connected to a solid(not perforated)piping system. If possible, the system should drain by gravity. Otherwise,it may be necessary to include a sump pump in the system. The ground surface should be graded to slope to the drainage inlets. As long as the pipe is of sufficient size, downspouts in the area may be connected to the drain system. Cleanouts should be included for maintenance of the system. h. Subsurface Water Drainage Systems. Shallow(sometimes "perched") subsurface water can cause soil-swelling resulting in foundation upheaval. This condition can often be mitigated by the installation of a subsurface water drainage system, often referred to as a"French"drain. Although a true "French"drain is simply a trench filled with clean stone or gravel, subsurface water drainage systems usually should include a perforated pipe at the bottom of the trench and a geotextile around the pipe and/or the aggregate in the trench to prevent fine-grained soils from reducing the effectiveness of the drain system. Cleanouts for maintenance of the system should be included. Gutters and downspouts should not be connected to this type of drain system. i. Moisture Barriers. Moisture barriers have been effectively used when migration of moisture under the foundation has either occurred or is anticipated. Moisture barriers can be either vertical or horizontal,but vertical moisture barriers are believed to be more effective,depending on the depth to which they are installed. Moisture barriers generally consist of impermeable plastic sheeting or other appropriate material that is attached to the edge of the foundation. Moisture barriers can be used in conjunction with Root Barriers and/or Subsurface Water Drainage Systems. 3. If the city hires a professional engineer to check another professional engineer's work and corrections are made as a result of this review the city may open itself up for future liability. Some of the sections of the Texas Engineering Practice Act that concern me the most are as follows: §131.152. Engineers Shall Be Objective and Truthful. (e) Engineers shall only issue work conforming with the board's sealing rules. However,an engineer, as a third party,may alter,complete,correct, revise,or add to the work of another engineer when engaged to do so by a client,provided: (1)the client furnishes the documentation of such work submitted to the client by the first engineer; (2) the first engineer is notified in writing by the second engineer of the engagement immediately upon acceptance of the engagement;and (3) any work altered, completed, corrected, revised, or added to shall have a seal affixed by the second engineer. The second engineer then becomes responsible for any alterations, additions or deletions to the original design including any effect or impact of those changes on the original engineer's design. §131.155. Engineers' Responsibility to the Profession. (c)The engineer shall not: a Page 3 1 (2) maliciously injure or atter to injure or damage the personal or profession reputation of another by any means. This does not preclude an engineer from giving a frank but private appraisal of engineers or other persons or firms ■ when requested by a client or prospective employer; §131.166. Engineers'Seals. (a) The purpose of the engineer's seal is to assure the user of the engineering product that the work has been performed by the professional engineer named and to delineate the scope of the engineer's work.The engineer shall utilize the designation "P.E." or the titles set forth in the Texas Engineering Practice Act (Act), §1.3. Physical seals of two different sizes will be acceptable: a pocket seal (the size commercially designated as 1-5/8-inch seal) or desk seal (commercially designated as a 2-inch seal)to be of the design shown in this subsection. Computer-generated seals may be of a reduced size provided that the engineer's name and number are clearly legible. (k) Work performed by more than one engineer shall be sealed in a manner such that all engineering can be clearly attributed to the responsible engineer or engineers. When sealing plans or documents on which two or more engineers have worked,the seal of each engineer shall be placed on the plan or document with a notation describing the work done under each engineer's responsible charge. (I) Licensed employees of the state, its political subdivisions, or other public entities are responsible for sealing their original engineering work; however, such licensed employees engaged in review and evaluation for compliance with applicable law or regulation of engineering work submitted by others,or in the preparation of general planning documents, a proposal for decision in a contested case or any similar position statement resulting from a compliance review, need not seal the review reports, planning documents, proposals for decision, or position statements. • 6 Page 4