Tag Archive for: FAQ

5 Types of Metal Roofing: Type, Structure, Environment

5 types of metal roofing: type, structure, environment. It is important to understand before selecting screws for your type of metal roof installation.

The majority of BDN self-drilling screws are designed for either metal roofing or wall cladding installations, with the exception of proprietary designs for specific purposes such as PolyXpand™ for plastic skylight fixings, or TRUSS-Tite™ for joining truss components on steel framing.

 

Common issues we see on high quality, expensive metal roofing sheets fixings are:

  1. Incorrect selection of screws, with issues ranging from length, drilling capacity, thread type, gasket, and more.
  2. Poor quality screws which are unfit for the location and environment installed in.
  3. Improper screws for metal roof installation – the majority of issues stem from insufficient knowledge of the product, not following installation guides and instructions, and most of all, carelessness. Don’t forget that choosing the correct tool for the job also plays an important part in proper installation.

 

How to choose screws for metal roof installation properly?

 

How to choose screws for metal roof installation properly?

Before any installation, understand the type of structure, material, and environment we are dealing with. Since we are talking about screws for metal roof installation, determining the type of metal roof will be first priority.

 

  1. Is it a single sheet insulated panel?
  2. Are there any skylight panels installed in between sheets, and if so, what type of material are the skylights?
  3. What is the thickness of the sheet, and how thick is the insulated portion underneath?
  4. Color of the sheet and should the screws have to come with matching head colors?

 

Understanding the type of metal roofing and structure type

Upon determining the type of sheet used, we then have to understand the type of structure it is affixed to.

  1. Are the purlins steel or timber?
  2. Thickness of the steel purlins?
  3. Are there any trusses involved?

 

Introduction to the 5 environmental classifications

We should then determine the kind of environment the building structure is built on.  Here at BDN Fasteners, we have categorized the kind of environments to the following based on its characteristics.  Scope of warranty for our products are also based on the category the environment is classified to.

Dry, Rural Areas –

  • Areas remote from the coast and sources of pollution; as well as all of the areas listed below.

Mild Urban or Rural Areas –

  • Areas with little to no chemical pollution, including but not limited to natural chemicals such as ammonia from livestock or carbon monoxide from log-fire.
  • Areas far from the coast with no impact from salt water spray.
  • Areas at least 2 kilometers away from any type of industry, light or heavy.

Light Industrial or Urban Areas –

  • Light industrial zones, light manufacturing, warehousing, distribution, or limited light intensity activity areas.
  • Built up areas constituted of high human population and infrastructures.
  • Areas at least 1~2 kilometers away from light industrial or urban areas.

Small Industrial Zones –

  • Areas located in or adjacent to small industrial zones.

Coastal Areas –

  • Areas located approximately 2 kilometers from the coast.

 

BDN Fasteners® Screws Surface Coating

 

Lastly, choosing the correct screws for metal roof installation is only half the job done, and it all comes down to how the installer completes the final touch, as an improperly installed screw is worse than none installed at all.

 

Above are basic guidelines for the novice builder or contractor to follow when making the correct fastener selection.   Since building sites differ from one another, additional factors may be required to take into consideration; it is best to contact an experienced salesperson or technician for on-site checks before making final decisions.

 

Learn more about BDN Fasteners >>
Internal Roof Insulation Installation with Self-Drilling Fasteners
How to use self tapping screws for metal?

 

Properly driven screw-BDN Fasteners® Made in Taiwan

Metal roof leaks around screws:

There are lots of contributing factors when it comes to roofing leaks.  A properly driven screw will have achieved the following steps and as a result, provide the perfect weather seal.

Driven straight, perpendicular to the material it is fastened on to.

Adequate, clean penetration with no excess swarf protruding or overhanging from the drilled hole.

Driven until the gasket is compressed firmly against the surface.

 

Below is a list of common causes of metal roof leaks.

 

1. Choosing an incorrect screw:

Metal roofing screws are usually designed for fixing thin roofing sheets onto steel purlins, trusses or timber underneath.  Depending on the thickness of steel underneath, correct drilling point sizes must be chosen in order to penetrate.  Most suppliers will provide a list with corresponding drilling capacities to their screws.  Read through the list carefully and don’t hesitate to ask questions.

The length of the screw is also important. The length of screw required can be calculated by adding the depth of the roofing sheet corrugation, plus the thickness of the purlin/truss underneath plus at least 2 to 3 full thread lengths to ensure proper fastening.  Don’t forget that the thickness of the bonded EPDM washer or Domed BAZ washer should also be taken into consideration.

Thread type should be considered.  A rule of thumb is, coarse threads for thinner sheets (<4.5mm), and fine threads for thicker sheets (>4.5mm).  This will ensure the fixing to have adequate pullout values against pressure from high winds or snow.

 

2. Overdriven screws:

The rubber gasket should seat firmly but not over compressed against the surface.  The rule of thumb is, the gasket should not be bulging at the sides of the washer flange, or even to the point of being squished.  Workers should take extra care while making an attempt to ensure a tight seal between the metal roofing and the screw head because an over-torqued washer loses its elasticity, breaks down prematurely, and oftentimes disintegrate due to over-exposure to the elements.

 

3. Under-driven screws:

This is an easy one.  An under-driven screw does not provide sufficient pressure to the washer to create a firm seal against the surface.  This may happen due to incorrect drilling tip capacity selection and therefore could not adequately penetrate the metal substrate underneath to reach the desired depth.

 

4. Misaligned or skewed drilling:

A misaligned or crooked driven screw will result in the rubber washers not seating properly against the surface, which means insufficient seal of the hole, or one side over compressed, resulting in premature damage to the gasket.  Another sometimes overlooked risk is the skewed side of the steel washer or hex washer flange digging in, deforming or sometimes even cracking the surface, which also contributes to leakage.

 

Properly driven screw

 

Some screws have extra features built in to enhance performance; oftentimes poor choice of fixings become the weakest link in a seemingly strong building structure.  BDN Metal-Tite® series roofing screws come with an enlarged hex washer flange, anti-static EPDM washer, double thread, Scratshank, and Ruspert anti-corrosive coating.

  • The large washer flange is designed so that the EPDM washer will remain fully covered after compressed.
  • Anti-static EPDM washers prevent galvanic corrosion.
  • The larger diameter upper thread close to the hex washer flange increases pullout values on thin metal sheets.
  • Scratshank clears out excess swarf, smooths out the drilled hole, and prevents damages to the EPDM.
  • Ruspert anti-corrosive coating fully protects the screw from weathering and extends the lifespan of the screw and the sheets it is affixed to.

 

Learn more about BDN Fasteners >>
Internal Roof Insulation Installation with Self-Drilling Fasteners
How to use self tapping screws for metal?

How to use self tapping screws for metal?

Self-Tapping and Self-Drilling screws are the bread and butter of our business and the most commonly known and used for fastening two different kinds of material, be it steel, timber, or plastic, and the list goes on.

BDN Fasteners offers TIMBER-Tite™ and TRUSS-Tite™ self-tapping screws.

TIMBER-Tite™ screws are designed for fixing metal roofing sheets or wall claddings to timber, whereas TRUSS-Tite™ is designed to fix steel roofs and floor trusses. Basically, all self-drilling and self-tapping screws are able to tap threads, where the main difference is that self-tapping screws normally come with either a blunt head, sharp point, or a reduced drill point.

 

Blunt headed screws such as the TRUSS-Tite™ is designed for truss components assembly, fixing into steel. These types of steel normally come with pre-punched or pre-drilled holes, and the blunt, slightly tapered leading threads makes it easier to fix the sheets down.

Frame Screw - TRUSS-Tite™ Fixing to steel roof and floor trusses, BDN FASTENERS®

 

Our sharp pointed TIMBER-Tite™ are designed for fixing roof sheeting to timber. The longer versions such as the T17CG1265C3N or T17CG1250C3N are designed for crest fixing and shorter versions such as the T17H1020C3N are designed for valley fixing. People ask why screws should be fixed down on the crest but not the valley. The main reason being water runs by gravity and flows to the lowest point, and if fixed on the valleys on rooftops, might increase the risk of water pooling around the screws and with time, cause rust.

Type 17 Timber Screws TIMBER-Tite™ Fixing roof sheeting to Timber and light metal. BDN FASTENERS®

TIMBER-Tite™ Fixing roof sheeting to timber: crest fixing fasteners

TIMBER-Tite™ Fixing roof sheeting to timber: valley fixing fasteners

Shorter self-tapping screws which come with what we call a “reduced” drilling point, provides the same function as a sharp drilling point, but drills faster through thin metal sheeting, and is much more effective at clearing off excess swarf, as it is difficult if impossible to add flutes on smaller sharp pointed screws to due manufacturing limitations.

 

Scratshank: Swarf Free. Removes sealing washer damaging swarf during installation.

For roofing sheet fixing screws, always check if they come with a knurled, fluted, or slotted shank, and if the upper threads are larger in diameter compared to the lower threads. You might notice that the majority of BDN self-drilling and self tapping screws for metal are equipped with both. The larger diameter upper threads provide good pullout strength for the whole setup under high winds and the slotted Scratshank design clears out excess swarf which might damage EPDM washers if leftover, which could result in leaks.

 

Learn more about BDN Fasteners >>

Internal Roof Insulation Installation with Self-Drilling Fasteners
How to use self tapping screws for metal?

 

Self-tapping screw head types

 

screw head types: 10 different self tapping screw types

Self-Tapping Screw Head Types

A self-tapping screw has the ability to tap threads as it is driven into the material. It is often used only to describe a specific type of thread-cutting screw intended to produce threads in various types of materials, with sheet metal and wood being the most common.

BDN Fasteners offers a range of self-tapping screws. The screws come with either a self-drilling tip for metal or pointed tip for timber. After the tip creates a pilot hole, the thread then taps into the  metal or wood the screw is affixed to.

 

Regarding head types, screws are available in many different head types.  Some head types are very application-specific, while others are more versatile for general applications.  Head types are usually manufactured according to set standards according to the region used, though some might tweak or even tailer the design here and there in order to meet special requirements.

 

BDN Fasteners are manufactured according to the tried-and-true Australian AS standards, offering a good balance between cost and performance, and backed with an industry-leading warranty.

10 Screw Head Types

HEAD STYLE

DESCRIPTION

screw head types: bugle head

BUGLE HEAD

In the smaller gauges up to 8gauge, this head style is generally used for plasterboard as it does not damage the face of the sheet. The 14-gauge screws with this head style are often used for landscaping and fixing heavy duty decking boards.

screw head types: button head

BUTTON HEAD

Screws with this head type are used for stitching thin steel together and the large head provides a good clamping force on the materials being fixed.

screw head types: countersunk (csk) head with ribs (nibs)

COUNTERSUNK (CSK) HEAD WITH RIBS (NIBS)

This head style is used in a broad range of timber applications where a flush finish is required for the fixing, and the ribs countersink the screw into the timber. It also comes in a variety of drive types depending on the application.

screw head types: countersunk (csk) head without ribs (nibs)

COUNTERSUNK (CSK) HEAD WITHOUT RIBS (NIBS)

This head style is generally used with screws that are fixing steel, where a countersunk recess has been pre-drilled.

screw head types: flat head / flush head

FLAT HEAD / FLUSH HEAD

This head style is a low-profile type typically used where cladding is to be fixed over the top, including where plasterboard is fixed to a steel house frame. It is imperative that the head sits absolutely flat.

screw head types: hex flange head

HEX FLANGE HEAD

This head style is used for a broad range of applications including roofing, cladding and timber fabrication, and comes in a range of gauges for heavier duty applications.

screw head types: pan head

PAN HEAD

This head style is used with general purpose fasteners for fixing thin steel to steel or timber substrate.

screw head types: self embedding head

SELF EMBEDDING HEAD

This head style is mainly used for fixing 3-6mm thick cladding such as Cement Sheet or Blue Board, and the ribs under the head countersink the screw into the material for a flush finish.

screw head types: trim head

TRIM HEAD

This head style is normally used for decking or picket applications where a smaller head is required to avoid splitting the timber when it is installed.

screw head types: wafer head

WAFER HEAD

This head style is mainly used for fixing a variety of generally lighter materials to a steel or timber substrate.

 

 

Learn more about roofing screws >>
Internal Roof Insulation Installation with Self-Drilling Fasteners
How to use self tapping screws for metal?

6 Benefits of Using Roofing Screws with Rubber Washer

How to Master Use of Self-Drilling Screws_BDN.001

Self-drilling screws – commonly known as Tek screws – are some of the most widely used metal fasteners in the building and construction industry.

How to Master Use of Self-Drilling Screws_BDN.001

Tek screws or self-drilling screws come with an additional pair of bladed flutes which extends from the threaded portion of the body all the way to the drilling tip.  The purpose of this is to combine the drilling and tapping function onto the same screw, thus eliminating the need to pre-drill pilot holes and tap threads.  Drill, tap and fasten are completed in one go, saving time and money.  The best Tek screws come with various types of surface treatments to cope with the environment and provide weathering resistance to itself and the fastened substrate.

Tek screws are popular for many general sheet metal applications like roofing, cladding, and HVAC, etc.

Larger Tek screws (No.3 Tek and above) are strong enough to penetrate 12~20-gauge galvanized steel, as well as 3/8” to ½” (10~12.5 mm) structural steel and can be used on various civil and naval engineering applications.

What is the best way to use Tek Screws?

To ensure optimum use and extended lifetime, here are some tips and recommendations for fastening Tek screws successfully onto various kinds of metal material.

  • Choose the right size Tek screw to match the material you are working with.
    Make sure that the Tek screw drill point capacity exceeds the thickness of the material to be drilled.  Failing to do so may result in burnt out or broken drilling tips.
  • Power drills with adjustable clutch settings are better suited for use with Tek screws on light sheet metal than Impact drills.
    The hammering action generated by impact drills can cause metal dimpling or oil canning deformations on lightweight metal sheets.
  • Do not overtighten the Tek screw and washer when fastening them onto sheet metal. The washers should be compressed just enough to fill any uneven surface to provide a perfect seal.
    Two things can happen if the washers are over-compressed. One, the sheet panel may deform from overtightening, and two, the exposed portion will be exposed to the sun and the elements, which accelerates the weathering process and reduces lifespan.
  • When fastening Tek screws onto hardened galvanized or structural steel, set your (cordless) power drill clutch speed to approx. 1500 rpm, and apply steady, consistent, pressure throughout the process.
    Drill speed exceeding 2300 rpm or more can result in premature drill point wear or burnout, causing it to lose its function.

Do not compromise the quality and workmanship of your construction projects.  Your building is only as strong as its weakest fastener.  Choose only quality self-drilling screws from a reliable Tek screw manufacturer – Choose BDN Fasteners today, every day.

Self-Drilling Screw Manufacturer. BDN FASTENERS®

Fastening sheet metal is a technical process that not only requires expertise, but also the most optimal screws – specifically self-drilling sheet metal screws. These screws feature sharp threaded shanks and tips that pierce easily through solid metal surfaces and other sturdy materials.

Self-drilling sheet metal screws come with pointed drilling tips designed to penetrate metal without the need for pre-drilled pilot holes.

Without the need for pilot holes, self-drilling screws save installation time, eliminates the extra cost for labor and drill bits. This cost-saving feature and additional advantages make them an excellent choice for metal building construction.

Features to Look Out for When Purchasing Self-Drilling Sheet Metal Screws

Like any hardware, self-drilling sheet metal screws come with various features. But whatever type of self-drilling sheet metal screw you need for your project, it’s best to go for screws that have:

  • Corrosion-Resistant capability

As many tradies know, rusty screws are a real pain to deal with, not to mention an eyesore. Rust significantly reduces the strength of metal structural elements, reducing the thickness, and even leaving holes in components. It is also difficult to contain rust once it starts to spread, which is why self-drilling sheet metal screws with Corrosion-Resistant capabilities are in high demand.

As part of our quality assurance policy, all BDN Fasteners self-drilling screws are sent to SGS for regular Kesternich (7 cycles) and Spray Salt Tests (1000hrs).  Going through regular testing demonstrates our commitment to quality and the results prove consistent product quality.

  • Corrosion-Resistant surface treatment

Self-drilling sheet metal screws with proper Corrosion-Resistant surface treatments last longer against the deteriorating effects that occur from weathering.  Such exposure can negatively affect the performance of various components and increase the possibility of failure in the long term.

BDN Fasteners self-drilling sheet metal screws come with Class 3 Corrosion-Resistant coating – designed to cope with even the most challenging of environments.

  • Corrosion-Resistant accessories

Self-drilling sheet metal screws should also come with accessories that prevent the possibility of rust.  BDN Fasteners self-drilling screws come with optional pre-assembled weatherproof washers such as DEKS Dekseal® Trueblue®, 100% weather sealed washers.  These washers provide the perfect seal between the screw and sheet metal, are anti-static to reduce the possibility of rust, and come with a 20-year warranty that will outlast the life of most sheets – a must for construction projects.

Find High-Quality Corrosion-Resistant Sheet Metal Screws at BDN Fasteners

Roofing Screw-BDN FASTENERS-Packaging

 

At BDN Fasteners, we say that your sheet metal is only as long-lasting as the fasteners it is affixed to, which makes all the difference between a good or mediocre project.

BDN Fasteners offer an extensive range of Corrosion-Resistant self-drilling sheet metal screws in various lengths, sizes, and specifications, suitable for a host of applications.

Special features of our self-drilling sheet metal screws include:

  • Patented Trident Self-Drilling Point.
  • Designed to work with DEKS Dekseal® Trueblue® 100% Weather-Sealed Washers.
  • AS3566 Class 3 Corrosion-Resistant surface treatment.
  • SGS Certified: 1000hrs Spray Salt Test and 7 Kesternich Cycles.

As a leading supplier of sheet metal screws in Asia, we maintain strong relationships with dealers, distributors, and project managers, providing the correct fastening solutions for their needs.

For more information and inquiries about our products, contact us today.