As modern times come and new technology comes the more accurate and more efficient surveying has become. Surveyors used to use two posts with a chain

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1 Construction Layout Expert Construction Layout by Professional Engineers Typical Construction Layout Survey includes the following Stake out lot corners, stake limit of work and stake location of construction trailer (clear of all excavation and construction) Stake out reference points and markers that will guide the construction of new structures Verify the location of structures during construction; Provide horizontal control on multiple floors. Conduct an As-Built survey: a survey conducted at the end of the construction project to verify that the work authorized was completed to the specifications set on plans. Land surveys and surveys of existing conditions are generally performed according to geodesic coordinates. However for the purposes of construction layout a more suitable coordinate system is used. When preparing for a construction stake out, we have to convert from geodesic coordinates to the coordinate system used for that project. For construction stake out to construct buildings, an arbitrary system of grids is often established so as to correspond to the rows of columns and the major load-bearing walls of the proposed building. The grids for the construction stake out may be identified alphabetically in one direction, and numerically in the other. The construction layout grids are usually but not necessarily perpendicular, and are often but not necessarily evenly spaced. Floors and basement levels are also numbered. Structures, equipment or architectural details may be located in reference to the floor and the nearest intersection of the arbitrary axes. In other types of construction projects, arbitrary "north-south" and "eastwest" reference lines that do not necessarily correspond to true coordinates may be established to prepare the construction layout. The nearly perfect squareness and north-south orientation of the 4,700 year old Great Pyramid of Giza, affirm the Egyptians' command of construction layout. 4,500 year old Stonehenge monument was set out by prehistoric surveyors using peg and rope geometry. 2,600 years ago geometric based techniques were used to construct the tunnel of Eupalinos on the island of Samos.

2 As modern times come and new technology comes the more accurate and more efficient surveying has become. Surveyors used to use two posts with a chain in between to measure distance, this technology could only account for the distance and not the elevation. Today GPS which uses radar and radio frequencies can measure the distance as well as accounting for the elevation differences. Surveying equipment, such as levels and theodolites, are used for accurate measurement of angular deviation, horizontal, vertical and slope distances. With computerisation, electronic distance measurement, robotic total stations, GPS surveying and laser scanning have supplemented (and to a large extent supplanted) the traditional optical instruments. A double right angle prism verifies grid patterns, isolating layout errors. Construction surveying (Construction Layout) in Ontario including Toronto (City of Toronto), Hamilton (City of Hamilton), Oshawa (City of Oshawa), Pickering (City of Pickering), Clarington (Municipality of Clarington), Ajax (Town of Ajax), Whitby (Town of Whitby), Brock (Township of Brock), Scugog (Township of Scugog), Uxbridge (Township of Uxbridge), Burlington (City of Burlington), Halton Hills (Town of Halton Hills), Milton (Town of Milton), Oakville (Town of Oakville), Brampton (City of Brampton), Mississauga (City of Mississauga), Caledon (Town of Caledon), Vaughan (City of Vaughan), Aurora (Town of Aurora), East Gwillimbury (Town of East Gwillimbury), Georgina (Town of Georgina), Markham (City of Markham), Newmarket (Town of Newmarket), Richmond Hill (Town of Richmond Hill), Whitchurch - Stouffville (Town of Whitchurch-Stouffville), King (Township of King) is to stake out reference points and markers that will guide the construction of new structures such as roads or buildings. These construction layout markers are typically staked out according to a suitable coordinate system selected for the project. Precise construction staking (layout) for underground sanitary sewer lines, storm drain lines, water lines, electrical lines, building corners, interior grid lines throughout the building, onsite fire hydrants, curb and gutter, walls/planters, catch basins, area drains. etc., is an important step in ensure horizontal and vertical accuracy to confirm the project is constructed as per the approved engineering drawings and plans for the proposed construction. We use the most expensive and technically sophisticated equipment including 3 D laser scanners, robotic total stations to locate all the points we might need for the construction layout, record information onsite to create CAD drawings.

3 GPS surveying instruments which establish location by receiving measurements from satellites and communicating with a known reference station are also used for plotting points and locations for the construction layout. Data collectors provide all the information for guiding 3 D laser scanners and GPS surveying instruments. Robotic total station is the industry standard for high accuracy construction layout and it needs only one person to shoot points and elevations to prepare the construction layout, saving time and obtaining information that might otherwise be dangerous to collect. We use robotic total station to 3 D contours for excavators and concrete placing equipment. We provide control points to contractors before they construct a project when no established points exist on a proposed construction site, provide benchmarks so the construction crew can use laser levels to set excavation elevations and setting grade required for the construction layout. During construction layout, we also set points for footings and pads and points on completed footings to locate foundation walls. Typical Scope of Work for a Construction Layout as follows Review the approved site plan to confirm that the site dimensions agree with the boundary survey. If the site plan is revised, verify and confirm the new values on the revised site drawings "work" to prepare the construction layout. Confirm site setbacks comply with the zoning requirements and the approved site plan. Locate grid line positions relative to the building face and position caisson locations relative to grid intersections. Establish horizontal and vertical control stations and prepare a coordinate list for all points from each control station. Confirm the source of the vertical datum of the drawings and establish a minimum of two temporary benchmarks (TBM) in close proximity to the site. Take redundant measurements and calculate closures and onsite double check. As an independent, redundant check, run a level loop through the site control and close on to a second established municipal benchmark. Architect s review of the construction layout with final computed dimensions to confirm that the siting is correct prior to field layout. Close, reduce and double-check level loops and review of all construction layout performed after each field work. Confirm all points that are laid out on the construction layout have redundant ties or check measurements to eliminate blunders.

4 We require a digital file to prepare for construction layout. Also a hardcopy of the site plan marked Issued for Construction is required to prepare the construction layout. We have to verify the site benchmark elevations by leveling to an established municipal geodetic benchmark before commencing the field work for the construction layout. Elevations for temporary benchmarks are derived from a minimum of two established municipal geodetic benchmarks. We use stable objects like the finished floor slab of an adjoining building or a spike in a tree that is outside the construction area to establish temporary benchmarks. Temporary benchmarks cannot be established on objects that can move like survey monuments, fire hydrants, utility pads, posts and poles. We use published dimensions only and do not scale drawings or interrogate digital files for dimensions without proper checks. Construction Layout for Subsurface Utilities Safety hazards must be assessed and the appropriate safety precaution must be taken in accordance with the Ontario Health and Safety Act before any subsurface field work including underground sanitary sewer lines, storm drain lines, water lines, and electrical lines begin. Subsurface Utility Layout for underground sanitary sewer lines, storm drain lines, water lines, electrical lines is the process of gathering underground information about a manhole and its associated attributes. Center of lid shall be coordinated Type/purpose of utility, ie. Storm, sanitary, hydro, etc. Size/diameter of pipe and chamber Depth to invert, top of pipe, top of spindle, etc. Location of pipe inlet and outlet Chamber Wall location if required Sub-surface utility locates for underground sanitary sewer lines, storm drain lines, water lines and electrical lines are governed by Sub-surface Utility Engineering practices.

5 We stake each drainage structure independently of each pipeline. Each structure will require a reference line for alignment and grade, consisting of at least one hub on opposite sides of the drainage structure. The hubs should have equal offsets and be a minimum of 3 m from the reference point. The reference line should mark the centerline of junction boxes and drop inlets, and the inside back wall of catch basins. Grades should be set and referenced from the hubs to top of structure for junction boxes and catch basins, and flow line of grate for drop inlets. Construction Layout for Retaining Walls, Noise walls and Reinforced Earth Walls Retaining walls, noise walls and reinforced earth walls are staked with a reference line to the face of the wall or as noted in the structure plans or as otherwise needed for construction. Existing ground elevations shown in the plans shall be verified for accuracy. For pile/panel type walls three offsets shall be provided for each pile. All critical elevations shall be referenced, including, but not limited to, top of wall/ coping, bottom of shaft/pile, etc. Construction Layout for Ditches Drainage ditches are located at the toe of fill sections to provide a controlled channel to carry storm drainage. Construction layout for ditches provides the location, depth and width of storm drainage channels so that the storm drainage channels effectively collect and distribute storm water.

6 Construction Layout for High-rise Buildings Including Condominium Apartment Buildings and Office Towers We prepare the following for construction of high-rise buildings including high-rise condominium apartment buildings and office towers in Toronto (City of Toronto), Hamilton (City of Hamilton), Oshawa (City of Oshawa), Pickering (City of Pickering), Clarington (Municipality of Clarington), Ajax (Town of Ajax), Whitby (Town of Whitby), Brock (Township of Brock), Scugog (Township of Scugog), Uxbridge (Township of Uxbridge), Burlington (City of Burlington), Halton Hills (Town of Halton Hills), Milton (Town of Milton), Oakville (Town of Oakville), Brampton (City of Brampton), Mississauga (City of Mississauga), Caledon (Town of Caledon), Vaughan (City of Vaughan), Aurora (Town of Aurora), East Gwillimbury (Town of East Gwillimbury), Georgina (Town of Georgina), Markham (City of Markham), Newmarket (Town of Newmarket), Richmond Hill (Town of Richmond Hill), Whitchurch - Stouffville (Town of Whitchurch-Stouffville), King (Township of King) Construction Layout for Shoring Piles/Rakers Construction Layout for Servicing/Laterals (Centreline & Bldg Corners) Construction Layout for Excavation Construction Layout for Footings 3 D Slab Edge Monitoring Construction Layout for Accurate Curb Construction Site Grading Layout and Final Confirmation Construction Layout for New Homes We have many years of experience in providing construction for layouts for subdivisions and custom build homes. Typical construction Layout for a new home consists the following: Mark the exterior corners of the foundation walls Once the original pins placed to mark the corners of the foundation walls are buried inside the footings, it is critical to re-establish these points on the top surface of the footings to building the foundation walls at the right location. Since all the heights indicated on the building permit drawings are relative to the ground floor level it is very crucial to mark the exact level of the ground floor. Check Finished Floor/Top Wall Elevations

7 Construction Layout for Bridges Construction Layout for a bridge will contain two reference lines for each end bent, interior bent, and the long chord line. A minimum of two temporary benchmarks are required to remain in place throughout the entire bridge construction. One benchmark is to be used for substructure and one for superstructure. On grade separation structures, a point of minimum vertical clearance may be shown on the general drawing. If shown on the plans, the elevation of this point shall be verified at the time of bridge layout. Construction elevations are furnished from Structure Design for all bridges except cored slabs and should be used as follows: Bottom of slab grades will be used to determine build ups at tenth points along each girder of each span. (For longer spans 20th or 30th points may be require; this will be given in the construction elevation printouts.) After camber has been checked, necessary corrections made and diaphragm connection bolts tightened, elevations should be determined on top of girders at each tenth point and are used in computing build-up heights. The effect of the sun can significantly change girder camber. Levels should be run either early in the morning or on a completely overcast morning. Deflections shown in the deflections tables are used in the required computations. Build-up height at a tenth point is computed as follows: + final bottom of slab elevation + deflection due to weight of slab + deflections due to weight of parapet, rail, and F.W.S. - top of girder elevation (determined in field) The algebraic sum of these values equals the height of build-up above the top of girder. In some cases, this value will be minus indicating the girder flange projects into the slab. The build-up heights for the entire bridge can be computed and listed in a field book well in advance of any forming operation. These heights can be marked on the top of girder at the proper tenth point. The Contractor should be made aware that the computed height is at the centerline of girder and will vary at each side of the build-up depending on the crown slope and flange width. Overhang grades are given for every 1.5m interval along the lower outer most point of the proposed overhang.

8 These grades are given in respect to centerline stations. In order to correctly locate these overhang locations, a reference point on each of the proposed overhangs must be determined according to centerline station, from which the other overhang points can be laid off. Header grades are given along the skew of the proposed header, to the finished top of slab grade. These elevations can be used as listed when grading headers located over the bearing points. However, when a header is located on a span, movement of the header will occur as the beams deflect during the deck casting operation. This type of header is known as a floating header. Floating headers are best graded by measuring up the deck thickness for the bottom of slab elevation at each point the header crossed a beam. When the header does not cross a beam at a previously calculated build-up, interpolation should be used. The header must reflect many changes in the transverse slope of the deck which may occur between beams. Drilled shafts should be staked only after bridge stake out is complete. Each drilled shaft should be referenced individually so that casing and reinforcing steel alignment can be checked during drilling and casting operations. Each drilled shaft layout will contain two reference lines with two reference points on either side. Approach slab grades also are given to the finished slab grade. It is important to check a point on the actual deck, at either end of the structure, which is relative to a given approach slab elevation in order to determine any necessary minor adjustment to the approach slab. Grades should be checked utilizing a stringline off deck. All critical construction layout points must be recorded and independently verified to ensure their validity and correctness. All match points must be verified to satisfy existing conditions. Layout/offset points and the reference feature must be recorded digitally for verification & future reference.

9 Typical Fees for Construction Layout for Projects: $295 plus Field $95 per Hour Minimum 4 Hours. If we have prepared the survey plan $295 fee will be waived. Still have questions? Call Us Anytime (24/7) Text Messages buildingexpertscanada@yahoo.com Construction Layout Experts BUILDING EXPERTS CANADA Professional Engineers Ontario Certificate of Authorization # Finch Avenue East Toronto ON M1S0C2 We offer Construction Layout Service in Ontario including Toronto (City of Toronto), Hamilton (City of Hamilton), Oshawa (City of Oshawa), Pickering (City of Pickering), Clarington (Municipality of Clarington), Ajax (Town of Ajax), Whitby (Town of Whitby), Brock (Township of Brock), Scugog (Township of Scugog), Uxbridge (Township of Uxbridge), Burlington (City of Burlington), Halton Hills (Town of Halton Hills), Milton (Town of Milton), Oakville (Town of Oakville), Brampton (City of Brampton), Mississauga (City of Mississauga), Caledon (Town of Caledon), Vaughan (City of Vaughan), Aurora (Town of Aurora), East Gwillimbury (Town of East Gwillimbury), Georgina (Town of Georgina), Markham (City of Markham), Newmarket (Town of Newmarket), Richmond Hill (Town of Richmond Hill), Whitchurch - Stouffville (Town of Whitchurch-Stouffville), King (Township of King).