About Metal Roofing
Tags: Architectural METAL ROOFING MATERIALS
The widespread use of metal roofing, waterproofing and thermal
insulation of its features are constantly improved and perfected.
Considerations from the water, ripples from the original low-roof, to
today's high corrugated roof; from the original self-tapping screws
used the connection method to today's dark button connection. From
insulation considerations, the development of the composite plate from
the board. Above aspects of the development, and gradually to meet the
owners of the requirements of the selection of metal roofing, metal
roofing and thus further promote the use and development.
⒈ low and high corrugated roofing corrugated roofing
By plate tectonic classification, corrugated metal roof can be divided
into low and high roof corrugated roof. The difference between these
two different rib high, so the drainage effect is different. Because of
high corrugated metal roof high roof panel ribs, drainage relatively smooth,
generally applicable to relatively gentle slope of the roof the roof,
usually around 1:20 roof slope, minimum slope to be 1:40. Corrugated
roof and low roof are generally used for steep slope roof, common roof
slope 1:10 or so. Leaking roof metal roofing system is hidden issue,
but also a more difficult problem. Light steel structure and the
difference between ordinary steel in its structure to allow a greater
deformation, mainly in the deflection and the lateral column. On the
one hand, if the deflection is too large, will lead to roof water, and
water phenomenon, is further exacerbated by the deflection, leading to
more serious leakage. On the other hand capitals sway too much, will
lead roof of the occurrence of dislocation joints, causing leakage, the
site of leakage is difficult to determine, and may change, so
maintenance is very difficult. For these cases, the metal roof to
prevent water leakage, the best high corrugated roofing, roof slope, or
try to make bigger.
(A) low ripple roof (b) high corrugated roof
⒉ screws exposed roof and roof dark button
Classified according to the form of connection, the metal roof can be
divided into the screw exposed roof and roof dark button. Screws
exposed roof, the roof through the self-tapping screws and purlins
fixed together and painted in the self-tapping screws around the
sealant. This connection there are several problems: first, self-
tapping screws were exposed, there will be rust phenomenon, affecting
roof appearance; second, the construction of the large number of hard
to find leak sealant coating phenomenon, which lead to leakage there;
Third, because sealant aging, over time there will be leakage; fourth,
connected along the flow direction of the lateral roof, and roof
lateral connections compared to more cause leaking. Practical
application show that the connection of the roof, basically there will
be water leakage. To solve this problem, in recent years appeared dark
button connected to roof, roof lateral parts directly connected to the
metal roof fixed to the purlins and between the board and the board
through the fixture between the board and accessories clamping, thus
basically eliminating the hidden metal roof leakage problems, so this
roof has been widely adopted soon.
(A) screw exposed roof
(B) dark button roofing
⒊ single layer and composite steel plate roof plate roof
From the point of view of thermal insulation, metal roofing can be used
both single-layer steel sheeting, composite panels can also be used.
Steel plate is currently the most commonly used light steel roofing
materials coated with zinc by hot zinc coated steel sheet or color
steel plate, cold-formed by rolling into a variety of waveforms, with a
lightweight, high strength, earthquake, fire, construction and
convenient. But the single-layer thin steel plate, including the
coating, including, the thickness of about 0.5 to 0.6 mm, a common type
is the low ripple and high above the two types of corrugated roof, so
the board can not meet the requirements of thermal insulation . If the
selection in the design of this roof, the roof must be a separate
insulation layer below, under the care of stainless steel wire mesh, or
re-design within a layer of roofing panels, the roof between inside and
outside the board and then packing insulation materials, such as glass
fiber insulation cotton, wool, etc., generally the bulk density of
cotton insulation, the thickness should be based on the thermal
insulation required by the calculation. For the average industrial
plant, the choice of the thickness of 50 ~ 100mm, higher insulation
requirements for the workshop or office, you can also consider the
ceiling; for cold storage or cold storage and other special
requirements on the building insulation, should be properly increase
the insulation thickness of cotton. Another measure to meet the thermal
insulation is the direct selection better thermal insulation composite
panels.
(A) the word Al-connected
(B) tongue and groove insert
Aluminum composite panels connected with the word-and high population
into two. The outer layer is a high-strength galvanized sheet metal
plate or galvanized color steel color, core material is flame retardant
polystyrene, glass wool or rock wool, through the automatic molding
machine, using high-strength adhesive to glue the two one, by pressing,
trimming, slotting, blanking and forming composite board. It has a
general building materials can not have the excellent performance, both
with insulation, noise and other physical properties; and have better
mechanical properties of bending and shear. Specific performance
indicators in Table 6-1.
Table 6-1 performance composite plate
Thickness (mm) 5,075,100,150,200,250
Plate weight (kg / m2) 10.5 11.0 11.5 12.5 13.5 14.5
Heat transfer coefficient (k / ㎡ hc) 0.663 0.442 0.331 0.221 0.166
0.133
The average noise volume of R (db) 20 22 25> 27
The main features of composite panels in the following areas:
⑴ light weight, small size, with the traditional masonry, reinforced
concrete structure, the weight 15 to 30 times the volume decrease of 2
to 5 times.
⑵ composite layer and the sandwich board insulation materials are non
-burning material, the use of flame-retardant adhesive, has good fire
resistance.
⑶ superior performance insulation compound board, the noise intensity
can reach 41 ~ 56 dB, with the sandwich insulation material and
thickness vary, but common bricks, concrete, noise intensity of only 38
~ 44 dB.
⑷ sandwich composite plate of low thermal conductivity of insulation
materials to determine the composite sheet has excellent insulation
properties, thermal insulation in cold areas or buildings with special
requirements, according to the need to increase the thickness of
insulation material.
With the expansion of steel market, especially the development of
residential steel, metal roofing materials and the use of features have
made new demands, thus further promoting the development of the new
plate and new technology development, the overall trend is light
quality high-strength, but also has good water resistance and high
thermal insulation and sound insulation, the other must also beautiful
and durable and easy construction.