Construction method for large-span old factory building roof updating and reconstruction
By using crane baskets and cantilever platforms, the problems of difficult roofing operations, long construction periods, and high costs associated with large-span old factory buildings were solved, achieving safe and efficient roof renovation construction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA MCC20 GRP CORP LTD
- Filing Date
- 2023-12-19
- Publication Date
- 2026-05-19
AI Technical Summary
The construction of large-span old factory buildings faces challenges such as difficulties, long construction periods, and high costs, especially the pressure on construction safety and costs caused by the difficulty in securing safety ropes and the erection of full-span scaffolding.
The roof tiles, waterproofing layer, and wooden sheathing were removed using a crane basket and cantilever platform. The roof trusses were dismantled and reinforced on the ground using a crane. The cantilever platform was then installed for construction. The roof purlins, wooden sheathing, and waterproofing layer were installed on the cantilever platform. The cantilever platform was removed after the roof was replaced.
This reduced the amount of scaffolding erection and dismantling work and the cost of rental materials, shortened the construction period, reduced construction costs, and improved construction safety and quality.
Smart Images
Figure CN117513805B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a construction method for the renovation of old buildings, specifically a construction method for the renovation and reconstruction of the roof of a large-span old factory building. Background Technology
[0002] In urban renewal projects, some large industrial relics are required to be preserved as part of the city's historical memory. The roofs of some large factory buildings need reinforcement, renovation, or replacement, making the reinforcement of large-span roof trusses unavoidable. Due to the large spans and generally heights exceeding 15 meters of these old industrial buildings, and the years of disrepair, construction workers face numerous difficulties working on the roofs. There is no place to secure safety ropes, compromising safety. If full-scale scaffolding is erected indoors for roof reinforcement and repair, the project would be enormous, time-consuming, and extremely costly. Summary of the Invention
[0003] The purpose of this invention is to provide a construction method for the renovation and upgrading of large-span old factory roofs, so as to solve the problems of difficult construction, long construction period and high cost of large-span old factory roofs.
[0004] The present invention is implemented as follows: a construction method for the renovation and upgrading of the roof of a large-span old factory building, comprising the following steps.
[0005] a. Use a crane basket to remove large-span roof tiles, waterproofing layers, and wooden planks.
[0006] b. Use a crane to dismantle the roof truss and lower it to the ground platform.
[0007] c. Use a crane to remove the roof panels.
[0008] d. Reinforce the roof truss on the ground.
[0009] e. Use the roof truss web members as supports to install a cantilever platform on the roof truss.
[0010] f. Use a crane to lift the roof truss and install the reinforced roof truss back in its original position.
[0011] j. Construction workers used the cantilever platform to install roof purlins, wooden sheathing, waterproofing layer, and roof panels.
[0012] h. After the roof renovation is completed, the cantilever platform will be removed.
[0013] The cantilever platform includes a horizontal frame, diagonal braces, a platform board, and a safety frame. The horizontal frame is located on both sides of the roof truss and is fixed to the web members of the roof truss. The diagonal braces are inclined between the horizontal frame and the web members of the roof truss. The platform board is laid on the horizontal frame, and a safety frame perpendicular to the horizontal frame is set at the edge of the horizontal frame.
[0014] The horizontal frame includes horizontal bars and connecting rods. The connecting rods are located at the ends of the horizontal bars and connect all the horizontal bars in the length direction of the connecting rods. The horizontal frame is set in the middle of the height direction of the web members in the mid-span of the roof truss.
[0015] A horizontal bar is installed on both sides of each web member of the roof truss, and the two horizontal bars are fixed to the web member by bolts; the lower end of the diagonal brace is fixed to the lower chord of the roof truss by a fixing seat.
[0016] The base includes a horizontal plate and a vertical plate. The vertical plate is perpendicular to the middle of the horizontal plate. A vertical end plate is welded and fixed to the lower end of the diagonal brace. The end plate is attached to the vertical plate and the end plate and the vertical plate are fixed by bolts.
[0017] Before the roof truss is unloaded, the transport flatbed truck is parked in the designated location in advance. The hoisted roof truss is then unloaded directly onto the transport flatbed truck and transported to the component storage area on site. During transportation and storage, the roof truss is supported on both sides with wooden blocks to keep it in a vertical position, and sleepers are placed at intervals at the bottom.
[0018] When dismantling the roof, first select one roof panel and break it manually. After breaking it, drill holes at the four corners of each roof panel to serve as fixing points for the wire rope during hoisting. For severely damaged panels that cannot be lifted by the crane through the holes, cut the connection manually and add a channel steel base support at the bottom of the roof panel. After connecting the wire rope to the channel steel base support, use a crane to lift it to the ground.
[0019] Flashing is installed at gutters, skylights, roof openings, ridges, and gables.
[0020] This invention employs a cantilevered working platform, which significantly reduces the amount of scaffolding erection and dismantling work and the cost of renting temporary materials. The cantilevered platform is installed on the roof truss web members, without altering the truss's stress distribution, eliminating the need for additional truss reinforcement measures. Interior wall repairs can be carried out concurrently with roof construction, greatly shortening the construction period and reducing costs. Because workers operate on the cantilevered platform, worker safety is effectively guaranteed, and installation speed and construction quality are improved. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the cantilever platform of the present invention.
[0022] Figure 2 This is the present invention. Figure 1 AA view.
[0023] Figure 3 This is the present invention. Figure 1 A magnified view of position B.
[0024] Figure 4This is a front view of the cantilever platform of the present invention installed on the roof truss.
[0025] In the diagram: 1. Roof truss; 2. Cantilever platform; 1-1. Top chord; 1-2. Bottom chord; 1-3. Web member; 1-4. End plate; 2-1. Horizontal member; 2-2. Connecting rod; 2-3. Diagonal brace; 2-4. Safety frame; 2-5. Horizontal plate; 2-6. Vertical plate. Detailed Implementation
[0026] The present invention provides a construction method for the renovation and upgrading of the roofs of large-span old factory buildings, comprising the following steps.
[0027] a. Use a crane basket to remove large-span roof tiles, waterproofing layers, and wooden planks.
[0028] A 50-ton crane was used to dismantle the roof. The crane lifted a basket, and the demolition personnel were inside the basket to remove the roof tiles, waterproofing layer, and wooden planks.
[0029] b. Use a crane to dismantle roof truss 1 and lower it to the ground platform.
[0030] The concrete roof truss 1 was dismantled using a 50-ton truck crane with four-point lifting. Roof truss 1 was reinforced with fir poles along its entire length and tied to the middle of the truss with wire.
[0031] The crane is positioned at the designated location and the steel wire rope is attached. After positioning, the bolt connections between the roof truss 1 and the column are manually separated. Then, a truck crane is used to lift the roof truss 1 as a whole to the ground, where it is manually disassembled and constructed.
[0032] Before the roof truss 1 is unloaded, the transport flatbed truck is parked in the designated location in advance, and the hoisted roof truss 1 is directly unloaded onto the transport flatbed truck, which is then transported to the component storage area on site. During the transportation and storage of the roof truss 1, wooden blocks are used to support the roof truss 1 on both sides to keep it in a vertical state, and sleepers are placed at intervals at the bottom.
[0033] c. Use a crane to remove the roof panels.
[0034] Before removing the roof panels, the surrounding buildings of the workshop were demolished and the site was cleared and leveled to allow the 50-ton truck crane to enter. The demolition personnel cleaned the fine aggregate concrete between each roof panel to ensure that the panels were separated. The construction personnel operated in the hoisting basket throughout the process and were not allowed to go down onto the roof.
[0035] After the roof is cleaned, the roof panels are removed. First, one roof panel is manually broken. After breaking, holes are drilled at the four corners of each roof panel to serve as fixing points for the wire ropes during hoisting. For severely damaged panels that cannot be lifted by the crane through the holes, the panels are manually cut and connected. A channel steel base is then added to the bottom of the roof panel. The wire rope is connected to the channel steel base and then lifted to the ground by the crane.
[0036] Dismantling is carried out from one end in sequence, following the order of the weld points between the precast panels and the roof truss 1, so that all weld points of the roof panels are cut off during the hoisting and dismantling of the roof panels.
[0037] d. Reinforce the roof truss 1 on the ground.
[0038] e. Using the web members 1-3 of the roof truss 1 as supports, install the cantilever platform 2 on the roof truss 1.
[0039] like Figures 1 to 4 As shown, the cantilever platform 2 includes a horizontal frame, diagonal bracing 2-3, a platform board, and a safety frame 2-4. The horizontal frame is located on both sides of the roof truss 1 and is fixed to the web members 1-3 of the roof truss 1. The diagonal bracing 2-3 is inclined between the horizontal frame and the web members 1-3 of the roof truss 1. The platform board is laid on the horizontal frame, and the safety frame 2-4 is set at the edge of the horizontal frame perpendicular to the horizontal frame.
[0040] The horizontal frame includes a horizontal bar 2-1 and a connecting bar 2-2. The connecting bar 2-2 is located at the end of the horizontal bar 2-1 and connects all the horizontal bars 2-1 in the length direction of the connecting bar 2-2. The horizontal frame is set in the middle of the height direction of the web bar 1-3 in the middle span of the roof truss 1.
[0041] A horizontal bar 2-1 is provided on both sides of each web member 1-3 of the roof truss 1. The two horizontal bars 2-1 are fixed to the web member 1-3 by bolts; the lower end of the diagonal brace 2-3 is fixed to the lower chord 1-2 of the roof truss 1 by a fixing seat.
[0042] The base includes a horizontal plate 2-5 and a vertical plate 2-6. The vertical plate 2-6 is perpendicular to the middle of the horizontal plate 2-5. A vertical end plate 1-4 is welded and fixed to the lower end of the diagonal brace 2-3. The end plate 1-4 is attached to the vertical plate 2-6 and the end plate 1-4 and the vertical plate 2-6 are fixed by bolts.
[0043] The cantilever platform 2 is fixed to the roof truss 1 and no holes are drilled in the roof truss 1 structure to prevent it from affecting the load-bearing capacity of the roof truss 1 structure.
[0044] The horizontal bar 2-1 is fixed to the web bar 1-3, and is limited and fixed by the web bar 1-3. The diagonal brace 2-3 is fixed to the base, and the base is placed on the lower chord 1-2 of the roof truss 1. The weight of the entire cantilever platform 2 is supported by the lower chord 1-2.
[0045] The safety frame 2-4 includes columns and safety nets installed on the columns, wherein the height of the columns is adapted to the height of the upper chord 1-1 of the roof truss 1, and the height of the columns is not higher than the height of the inclined upper chord 1-1.
[0046] f. Use a crane to lift roof truss 1 and install the reinforced roof truss 1 back to its original position.
[0047] j. Construction workers use the cantilever platform 2 to construct the roof purlins, wooden planks, waterproofing layer, and roof panels.
[0048] The roof purlins are veneered on the ground, and then a 25t truck crane is used to place the steel pipe purlins next to the designed position of roof truss 1. Construction workers stand on the cantilever platform 2 of roof truss 1 to install and position them, and tighten the screws or weld them in place.
[0049] The wooden planks are installed from the side span inwards, with workers installing them from the cantilevered scaffolding.
[0050] After the wooden plywood is installed, waterproofing treatment is carried out, and after the concealed inspection, the roll waterproofing is applied.
[0051] The metal roof uses standing seam aluminum-magnesium-manganese panels. The installation process for the roof panels is as follows: laying out lines → installation in place → interlocking → trimming the panel edges.
[0052] Layout: The planar control of the roof panels is achieved by positioning the fixed supports. After the roof panel fixed supports are installed correctly, only the control lines at the panel ends need to be set. Generally, the distance from the panel surface to the edge of the gutter is used as the control line, and the panel extension length should be slightly larger than the design dimension to facilitate trimming.
[0053] Installation and positioning: Hoist the roof panel to the installation position. When positioning, first align the control line at the end of the panel, then press the overlapping edge firmly into the overlapping edge of the previous panel, and fasten the other side into the aluminum alloy bracket. After completion, check whether the overlapping edges are tightly joined.
[0054] Sealing: After the roof panels are installed and adjusted, a special electric seaming machine is used to seal the edges. After sealing, a special clamp is used to fix the roof panel ribs.
[0055] Edge trimming: After the roof panels are installed, the edges need to be trimmed to ensure that the edges of the roof panels are neat and aesthetically pleasing. The length of the roof panel extending into the gutter should not be less than 100mm.
[0056] Flashing is installed at gutters, skylights, roof openings, ridges, and gables.
[0057] The flashing is made of the same aluminum-magnesium-manganese alloy sheet as the roof panel, and is shaped according to the requirements of different parts. The height of the flashing edge must ensure that rainwater does not flow into the room. Because aluminum-magnesium-manganese alloy has good weldability, the roof panel and the flashing at the opening edge can be welded together to create a completely sealed three-dimensional waterproof system.
[0058] Then, the edges are finished.
[0059] Roof panel end cap installation: End caps should be installed at gutters, ridges and eaves to prevent rainwater from entering due to wind.
[0060] Roof panel edge turning treatment: At the eaves of the roof, the ends of the roof panels need to be turned upwards using special clamps, with the angle controlled at approximately 45°, to ensure that rainwater at the eaves flows inwards and does not seep into the room from the end caps and flashing side.
[0061] Installation of drip edges in gutters: At the gutter, a continuous aluminum alloy angle is installed at the end of the roof panel as a drip edge. On the one hand, it can enhance the rigidity of the trough at the end of the panel; on the other hand, it can allow rainwater from the roof to drip into the gutter instead of seeping into the room.
[0062] h. After the roof renovation is completed, remove the cantilever platform 2.
[0063] After the installation on the roof is completed and accepted, the cantilevered scaffolding is dismantled. A lift truck is used for dismantling, and the horizontal frame, safety frame 2-4, and diagonal bracing 2-3 are dismantled in sequence.
[0064] This invention employs a cantilevered operating platform, which significantly reduces the amount of scaffolding erection and dismantling work and the cost of rental materials. The cantilevered platform 2 is installed on the web members 1-3 of the roof truss 1, without altering the load-bearing capacity of the roof truss 1, eliminating the need for additional reinforcement measures. Interior wall repairs can be carried out simultaneously with roof construction, greatly shortening the construction period and reducing costs. Because workers operate on the cantilevered platform 2, worker safety is effectively guaranteed, and installation speed and construction quality are improved.
Claims
1. A construction method for the renovation and upgrading of the roof of a large-span old factory building, characterized in that, Includes the following steps: a. Use a crane basket to remove large-span roof tiles, waterproofing layers, and wooden purlins; b. Use a crane to dismantle the roof trusses and lower them to a ground platform; c. Use a crane to remove the roof panels; d. Reinforce the roof truss on the ground; e. Use the roof truss web members as supports to install a cantilevered platform on the roof truss; f. Use a crane to lift the roof truss and install the reinforced roof truss back to its original position; j. Construction workers used the cantilever platform to install roof purlins, wooden sheathing, waterproofing layer, and roof panels; h. After the roof renovation is completed, the cantilever platform will be removed.
2. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 1, characterized in that, The cantilever platform includes a horizontal frame, diagonal braces, a platform board, and a safety frame. The horizontal frame is located on both sides of the roof truss and is fixed to the web members of the roof truss. The diagonal braces are inclined between the horizontal frame and the web members of the roof truss. The platform board is laid on the horizontal frame, and a safety frame perpendicular to the horizontal frame is set at the edge of the horizontal frame.
3. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 2, characterized in that, The horizontal frame includes horizontal bars and connecting rods. The connecting rods are located at the ends of the horizontal bars and connect all the horizontal bars in the length direction of the connecting rods. The horizontal frame is set in the middle of the height direction of the web members in the mid-span of the roof truss.
4. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 3, characterized in that, A horizontal bar is installed on both sides of each web member of the roof truss, and the two horizontal bars are fixed to the web member by bolts; the lower end of the diagonal brace is fixed to the lower chord of the roof truss by a fixing seat.
5. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 4, characterized in that, The fixing base includes a horizontal plate and a vertical plate. The vertical plate is perpendicular to the middle of the horizontal plate. A vertical end plate is welded and fixed to the lower end of the diagonal brace. The end plate is attached to the vertical plate and the end plate and the vertical plate are fixed by bolts.
6. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 1, characterized in that, Before the roof truss is unloaded, the transport flatbed truck is parked in the designated location in advance. The hoisted roof truss is then unloaded directly onto the transport flatbed truck and transported to the component storage area on site. During transportation and storage, the roof truss is supported on both sides with wooden blocks to keep it in a vertical position, and sleepers are placed at intervals at the bottom.
7. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 1, characterized in that, When dismantling the roof, first select one roof panel and break it manually. After breaking it, drill holes at the four corners of each roof panel to serve as fixing points for the wire rope during hoisting. For severely damaged panels that cannot be lifted by the crane through the holes, cut the connection manually and add a channel steel base support at the bottom of the roof panel. After connecting the wire rope to the channel steel base support, use a crane to lift it to the ground.
8. The construction method for the renovation and upgrading of large-span old factory building roofs according to claim 1, characterized in that, Flashing is installed at gutters, skylights, roof openings, ridges, and gables.