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HomeMy WebLinkAboutNB 3a SWIMMING POOL CD 06-01-81DATE: FROM: SUBJECT: June 1, 1981 NE~ BUSINqESS 6-1-81 Inter-eom Honorable Mayor and Council C~0nity Development Department Requirements of Swirmuing Pool Code BACKGROUND In response ~o a public concern expressed at the Council Meeting on Nay 18, 1981, the Building Official v~as asked to prepare a response to the following questions: 1. Why must a g~te have a key lock? 2. What is the justification for a 4 inch sand b~se under the pool decking? 3. Is there justification for a 5 foot walkway ~round a pool? 4. Can ~he drainage requirements be sgtisfied by requirements other than by language that would require a drain pipe or swale from the pool deck to the street? Responses to these questions from the Building Official are attached. DISCUSSION The requirement for a 'key" lock bas b CCh recommended for amendment. The requirement for 4 inches of sand under the deck is a condition contained in the swia~ingpool codes of other cities, but is not a uniform requirement. It is justified on the be~is of local soil conditions; however, unless the subsoil is properly treated, the sand will not accomplish the intended protection. Soil under the decking shouldbe properly treated by approved methods. F~ch site should be reviewed individually. The 5 foot walkway requirement around a pool should be a m~tter of the property owner's discretion with a 3 foot walkway ~eing adequate for safety. There is anccd ~o require drainage of the pool area to the street or an approved drainage way. In the majority of instances this should not necessitate installing a drain pipe or swale. Requirements of Swimming Pool Code June 1, 1981 Page Two RECOMMENDED ACTION It is recommended that the City Council direct the Community Development Director to advertise a hearing for the purpose of amending Ordinance No. 835 pertaining to the construction of swimming pools. The proposed amendment would accommodate the following: 1. Delete the requirement for "key" locked gates. 2. Establish a performance criteria for soil preparation under decking. 3. Establish a minimum three {3) foot walkway requirements around a pool. 4. Establish a performance criteria for deck drainage. RKF/dat Enclosures: Report of Building Official Letter - WA Soils Engineer May 21 Letter - Reagan & Kramer May 26 DATE: TO: FROH: SUBJECT: May 26, 1981 ! nter - C om Community Development Director George F. Reid, Building Official Uniform Swimming Pool Code, 1976, Report on Amendments Section 320 is being amended in proposed Ordinance No. 844, now at City Attorney's office, to omit the gate lock and key. This section is not being enforced on the advise of Deputy City Attorney, Dan Spradlin. The new provision is: "Gate shall be self closing and self-latching". Section 323. Ordinance No. 476 requires pools to be located not closer than five feet to a property line. The width of the deck had been a continuing matter of discussion particularly in relation to locating a pool close to an adjacent improvement such as the dwelling. If the decking is narrow anywhere around the pool particularly adjacent to an improvement, it is hazardous walking for a non-swimmer particularly a small child toddlin§ or on a tri-cycle. For two people to pass requires four feet (architectural standards). The usual city street side walk is four feet wide. A minimum five feet width (measured from the water) was proposed, Ordinance 835, for pool decking to be consistant with architectural and safety engineering practices and Ordinance No. 476. The five foot wide decking (measured from the water) per Ordinance 835 includes twelve inch wide coping and four feet of concrete behind the coping. The 4" sand under the decking has been seen in many pool structural drawings prepared by and signed by registered Civil Engineers. An alternate on such drawings is a concrete footing under the back side of the decking. These engineered drawings show pool and decking details for non-expansive soil conditions and expansive soil conditions leaving it up to someone to decide which detail to use. There have been concrete decks, placed directly on the soil or without the footing that heaved after the Tustin expansive soil became wet. The deck drainage was considered the minimum to avoid complaints of owners and adjacent property owners. Owner complaints resulted from water flowing against, or ponding against, the dwelling slab. Concrete slabs being porous results in damp carpets or lifting of floor tile or hardwood floor. Adjacent property owners complain about salty, chloronated, pool water flowing onto their property effecting their trees, shrubs, flowers, plants and turf. Both Uniform Swi,m~'~tng Pool Code, 1976 Report on Amendments May 26, 1981 Page Two owners ask why this was permitted to happen. Uniform Building Code Section 7012(d) is quoted: (d) Disposal. All drainage facilities shall be designed to carry waters to the nearest practicable drainage way approved by the building official and/or other appropriate jurisdiction as a safe place to deposit such waters. Erosion of ground in the area of discharge shall be prevented by installation of nonerosive downdrains or other devices. Building pads shall have a drainage gradient of 2 percent toward approved drainage facilities, unless waived by the building official. EXCEPTION: The gradient from the building pad may be 1 percent if all of the following conditions exist throughout the permit area: A. No proposed fills are greater than 10 fcct in maximum depth. B. No proposed finish cut or fill slope faces have a vertical height in excess of 10 feet. C. No existing slope faces, which have a slope face steeper than 10 horizontally to 1 vertically, have a vertical height in excess of 10 feet. There is a history of drainage problems. Ancient Roman Law and California Law as well as over 100 years of California case law has resulted in a few rules, one of which is: An upper owner may not divert surface waters on his land to the land of a lower owner by artificial means nor may he accelerate the flow by means of ditches or increase the drainage of his own land to the injury of the lower owner. He cannot, by interfering with natural conditions, cause surface water to be discharged in greater quantity or in a different manner onto the lower land than would occur under natural conditions. At the occasion of final inspection of a new dwelling or group of new dwellings, the inspector assures the grading will result in drainage away from the dwelling to a drainage swale thence to a Unifo~ Swi~a,~ng Pool Code, 1976 Report on Amendments ~,~.y 26, 1981 Page Three public drainage such as the street gutter. This drainage swale my be on the common property line. The installation of the pool changes the original grading. It can cl~ange the drainage toward the dwelling and onto the adjacent property. This can be avoided, thus the wording of the amendment. Having the words in the ordinance is easier to enforce. With the words out of the ordinance, the provisions are enforceable as there are other codes and laws. The State Health and Safe%y Code does not direct cities ~o adopt the Uniform Swimming Pool Code. Local conditions, such as expansive soil, is justification to include amendments effecting structural resistance to the destructive forces exerted by wet expansive soil. Uncontrolled splash water, irrigation and rain creates conditions for such forces. The Uniform Swinm%ing Pool Code primarily addresses the pool piping, pump, filter, heater, skinner, drains, inlet and outlet. The USPC states "The electric wiring and equipment shall comply with the current National Electric Code". The USPC states, "All design, construction and workmanship shall be in conformity with accepted engineering practices ..... ". This latter statement leads to non-uniformity and uniformity. Each city amends the USPC when it is adopted to prescribe the various structural elements of pools. In preparing such ordinances other local cities ordinances are copied to promote uniformity. The amendments keep changing as various unsafe or unsound conditions are enco~hutered. These conditions are related at monthly building official meetings and incorporated into the amendments at the next code adoption ordinance · The State Swimming Pool Act applies to public swiFraing pools, not to private pools. The provisions relate to health and safety and not to structural engineering design. The mimi~mn width of the pool decking is four feet (measured from the backside of the 12" wide coping). City Ls-Habra Yorba Llnda A~ND~NTS UNIFORM SWI~Ib~P(X~CODE ADOPTION ORDINANCE Sand Under Drainage 3! Approved deck drainage system or deck drains to nearest practical drainage way or street approves by the building official ..... no such drainage will run off on ac~joining property. 5! Use-Expansive Soil Details Slope to drain from pool as approved by the building official, Fullerton Huntington Beach County of Orange Costa Mesa Garden Grove 4! 4~ 8"x12" footing under outside edge of deck Assume expansive soil Plan check determines If use expansive soil details 4" sand under deck or use engineer expansive soil detail. Assume expansive soil No expansive soil Slope to drain from pool as approved by the building official. Use expansive soil details as shown on the registered civil engineers drawing. No drain requirements. Inspector uses judgement on drainage. He either okays as contractor proposes or directs other provisions. Drain to street gutter-slope away from pool, away from property line, and away frcm dwelling. Use surface swales or under deck drains. Similar drainage as Costa Mesa ~'~ WESTLAND /Lt ~ ~ ASSOCIATES ~V ~ Ltd. of California FOUNDATION ENGINEERING · ENGINEERING GEOLOGY 23101 TERRA DRIVE · LAGUNA HILLS, CALIFORNIA 926,53 · (714) 768-4466 May 21 , 1981 Project No. 1555 City of Tustin 300 Centennial Way Tustin, California 92680 Attention: Ci~y Council GENERAL GEOTECHNICAL REMARKS SAND FILL USE IMPACTS CONCRETE FLATWORK SUBCRADES Gentlemen: In response to an oral request of Mr. Darrell Cankema of Seiko Pools, we are pleased to issue this letter, for your consideration in addressing the effectiveness of requiring sand beneath concrete flatwork in your city. It is understood that this issue is scheduled for discussion by the Council, and it is our hope and belief that the following geotechnical data will be helpful to you. 1. Sand (typically 2 to 6 inches thick) is commonly used by contractors in preparing the subgrade supporting concrete pavements and flatwork. The impact of its use is both positive (DOES) and negative (DOES NOT) as identified below, end sand: a) DOES aid in facilitating a more uniform subgrade, especially on uneven hard ground, i.e., easier for the contractor. b) DOES help in curing concrete somewhat more easily, provided it is prewetted prior to the "pour". c) DOES NOT significantly alter the reduction of soil swelling, since the thickness is too thin. Rather, as much sa 12 inches (moderate swell) to 36 inches (critical swell) of sand would be required to negate expa.nsion effects beneficially. Most effective is soaking or presaturation of the soils at 10 to 20 percent above optimum moisture content at depths of 12 to 18 inches., depending on the type of construction uses. City of Tustin May 21, 1981 . Project No. 1555 Page 2 d) DOES NOT prevent slab cracking, since reinforcing must be used to transfer bending stresses (tension) resulting from uneven forces (uplifting or settlement). 2. The geotechnical considerations of swelling soil are most complex, and the assessment plus implementstion of corrective procedures is best left to the Soil or Founda- tion Engineer.- Depending on the circumstances, he may require chemical additives, soaking, removal and/or mixing with other m~terials at controlled water content and/or compsctive effort. In conclusion, we advise thst the potential misuse of sand beneath concrete in the hope of effectdng desirable benefits could indeed result in encouraging swelling by inviting easy access for near subgrade water via the sand stratum. In short, the "cookbook" approach of stipulating sand use as a "cure" for dealing with the adverse resctions of soil swell co61d easily backfire end reliance on a qualified Soil Engineer makes much more sense. LCC:jj Very truly yours, WESTLAND ASSOCIATES LTD. OF CALIFORNIA By: Leon G. Chaulet Foundation Engineer R.C.E. 17966 REAGAN & KRAMI!R STRUCI~URAL ENGINEERING May 26, 1981 City of Tustin 300 Centennial Way Tustin, CA 92680 Attention: City Council RE: General Structural remarks sand fill for concrete flatwork. Gentlemen: At the request of Darrell Gankema of Seiko Pools, I have reviewed the letter written by Leon Chaulet of Westland Associates LTD. of California dated May 21, 1981 and would like to make the following coLm~ent s; 1. I concur with Mr. Chaulet that the sand will not prevent slab cracking. I would like to add that slab cracking can occur from temperature changes and/or shrinkage of the concrete. 2. The most effective way we have found to insure satisfactory performance from concrete flatwork is to control the cracking by use of expansion joints and/or keyed construction joints; along with the use of reinforcing. In conclusion, we would like to stress that there are numerous other factors involved in the construction of concrete flatwork and the use of sand alone beneath the concrete would not provide satisfactory results. If I can be of any more service please call. Sincerely, David R. Kramer S.E. 2309 DRK/cw cc: Leon Chaulet