Preparation Work
Select Appropriate Tools: Prepare a high-precision steel tape measure with clear scales and high accuracy. The minimum scale should reach the millimeter level, and the length should be selected according to the size of the door opening, generally between 2 and 5 meters. At the same time, prepare a right-angle ruler to check whether the right angles of the corner of the wall and the door opening are standard. If possible, also prepare a laser rangefinder, which can measure distances more accurately, especially suitable for larger door openings.
Clean the Door Opening Area: Remove obstacles around the door opening, such as construction waste, dust, and sundries. For the protruding or uneven parts on the surface of the door opening, use sandpaper or a scraper to polish and trim them to ensure that the surface of the door opening is clean and flat for accurate measurement. Before installing the doors and windows, it is necessary to clean the obstacles in the door opening area. Otherwise, problems are likely to occur. For example, if the installation is not in place or not careful, there will be problems such as the door getting stuck when opening and closing during use.
Measuring the Width
Multi-point Measurement: Measure the width at three different height positions, namely the top, middle, and bottom of the door opening. Fix one end of the steel tape measure at the edge of one side of the door opening, ensure that the tape measure is perpendicular to the edge of the door opening, and then read the scale value corresponding to the edge of the other side of the door opening, and record the width dimensions of these three positions respectively.
Check the Deviation: Compare the three width measurement values. Under normal circumstances, the error of the door opening width required for the installation of the folding door should be within ±5 millimeters. If the deviation between the three measurement values exceeds this range, carefully check whether the door opening is deformed or uneven. It may be necessary to further repair the door opening, such as filling in the depressions or removing the protruding parts, to ensure the consistency of the door opening width.
Determine the Final Width: Select the smallest value among the three measurement values as the effective width of the door opening. This value will be used as the basis for selecting the width of the folding door to ensure that the gaps on both sides of the folding door are uniform after installation, and the door can be installed and used smoothly. Determine the final width before production to avoid wasting materials due to premature production.
Measuring the Height
Vertical Measurement: Measure the height at three different positions, namely the left, middle, and right of the door opening. Place one end of the steel tape measure at the edge of the top of the door opening, make it vertical downward, and then read the scale value corresponding to the position on the ground, and record the height dimensions of these three positions respectively. During the measurement process, ensure that the tape measure is vertical to avoid measurement errors caused by tilting. According to the vertical measurement, try to measure all the corners to ensure the accuracy of the folding door.
Check the Data: Similar to measuring the width, the error requirement for the height of the door opening of the folding door is also about ±5 millimeters. Compare the three height measurement values. If the deviation exceeds the range, check whether the top and the ground of the door opening are horizontal and whether the wall is vertical. If there are uneven or non-vertical conditions, corresponding adjustments are needed, such as using cement mortar to level the ground or the top of the door opening and correcting the wall.
Determine the Final Height: Take the smallest value among the three measurement values as the actual height of the door opening. This size will be used to determine the height of the folding door to ensure that the gap between the top of the folding door and the door opening is uniform and meets the installation requirements after installation.
Checking the Verticality and Horizontality
Check the Verticality: Use a right-angle ruler or a plumb line to check whether the two side walls of the door opening are vertical. Attach one right-angle side of the right-angle ruler to one side wall of the door opening and observe whether the other right-angle side is vertical to the ground; or use a plumb line, let the plumb line hang naturally, and observe whether the gap between the plumb line and the wall of the door opening is uniform to judge the verticality of the wall. If the wall is found to be not vertical, the deviation should be controlled within ±2 millimeters per meter. If it exceeds this range, the wall needs to be repaired. Check the details during the measurement to see if there are any omitted parts that have not been measured and if there are any parts that need to be re-measured.
Check the Horizontality: Use a spirit level to check whether the upper and lower edges of the door opening are horizontal. Place the spirit level on the upper or lower edge of the door opening and observe whether the bubble on the spirit level is in the center position. If the bubble deviates from the center, it means that the upper or lower edge of the door opening is not horizontal. For the non-horizontal situation, leveling treatment is required to ensure that the upper and lower edges of the door opening are on the same horizontal plane. The checked horizontal line should be appropriate and not deviate from the center line.
Multiple Measurements and Recordings
Multiple Measurements: To ensure the accuracy of the measurement, carry out at least two comprehensive measurements (including width, height, verticality, and horizontality). Each time you measure, try to start from different starting points and angles to eliminate accidental errors caused by the measuring tools or methods. Multiple measurements are to maintain the accuracy of the position, so that the window frame of the folding door can be well fitted during installation, and the door and window will look just right.
Record the Data: Record the data obtained from each measurement in detail, including the measurement position, specific values, and the problems found. Compare the data of different measurements. If the error is within the allowable range, the average value can be taken as the final size of the door opening; if the error is too large, carefully analyze the reasons, such as whether the tools were used improperly during the measurement or whether there are unstable factors in the door opening, and re-measure. The recorded relevant data can accumulate relevant experience for future measurements or installations, and also provide some references for the company when producing doors and windows.