Cracks in brickwork are an extremely common structural issue and the effects can become serious if the cracks are not immediately attended to. Getting the job done doesn’t have to be a stressful or difficult process: just follow the simple Twistfix guide and you’ll be repairing cracks like a pro before you know it!
The main issue with cracked brickwork is that the cracks provide the perfect route for wind-driven rainfall to penetrate masonry walls. When the weather is cold, water within the openings freezes and, as water expands by around 10% in volume when it turns into ice, the cracks are widened by the resulting pressure. The tiniest hairline cracks can thus become much larger very quickly, allowing more water to penetrate each time. More water means more expansion and the freeze-thaw cycle is set in motion, progressively worsening the issue and causing more damage to the bricks.
An effective filler, properly utilised, will get rid of any fissures and crevices that may have developed. When filling cracks in mortar joints, the process involves mechanically widening the cracks in order to allow for repointing of the wall at a sufficient depth using new mortars.
Cracks in brickwork require a purpose-made injection system to make sure that they are filled to an adequate depth.
PREPARE the cracks by using a vacuum or air-line. This is essential to remove loose or friable particles as the substrate must be free from dust, dirt and other contaminants if a long-lasting, successful repair is to be achieved.
MIX the injection mortar in strict accordance with the manufacturer’s instructions. Be aware that mixing adhesives causes an exothermic chemical reaction and the generated heat can limit workability of the product, meaning it has to be applied within a short time of being prepared. Users should therefore have everything they are going to need ready before this stage.
TRANSFER the injection mortar to a caulking cartridge that is fitted with a nozzle suited to the width of the crack to be filled. Nozzles are available that can inject resin into cracks a single millimetre wide.
INJECT the crack sealant as deep as possible, ensuring that the opening is completely filled from base to surface.
MATCH the colour of the repair to the substrate while the sealer is still tacky, using tinting agents or brick dust.
Twistfix supply all of the materials and tools required for repairing cracks in brickwork and, as always, we offer the most competitive market price. Order your crack sealing products from us today; browse the collection.
Spring has most definitely sprung and everyone is happy to feel a bit of warmth in the weather along with enjoying the bursting out of new life everywhere. Much of this new life is in the form of flora and those of us with gardens and/or allotments are being kept extremely busy!
A common sight (and smell!) for gardeners at the moment is a peacefully-smouldering bonfire but, as is well-known, fire has a habit of getting out of control when you least expect it…
A simple, fast and inexpensive job that could end up saving you a lot of time and money (not to mention cutting your risk of personal injury) is the application of a fire retardant treatment to any timber that could be at risk of burning, whether the risk is from a garden bonfire or anywhere else.
Twistfix are proud suppliers of the ThermoGuard system, which is one of the products on our April Special Offers section and is therefore available at an even more competitive price than usual.
What’s in the box?
ThermoGuard is a triple-protection system and comprises intumescent varnish base, preliminary activator and main top coat in three separate containers. Together, the formulae will coat around twenty square metres of timber, though this will vary according to the porosity of the wood.
How does it work?
In the event of fire, the intumescent base expands in size dramatically to create a strong, fire-resistant carbon char. This insulates the timber from the hottest flames, holding back smoke into the bargain. Stringent independent has ensured that the product meets all applicable health, safety and quality standards.
What are its aesthetic qualities?
All layers of ThermoGuard dry clear, letting the natural beauty of the timber shine through. You can choose from satin or matt and both provide UV protection as well as a durable surface perfect for anything from external cladding to internal woodwork.
So, it turns out that fighting fire with fire isn't such a good idea, at least when it comes to actual flames. Instead, use the triple-protection Thermoguard fire retardant varnish system, available now from Twistfix. Order now at the reduced price!
Remedial wall ties are much easier to install than most people give them credit for; the process can actually be broken down into three very simple steps.
The wall ties we supply have been designed by Thor Helical to provide the most professional results every time, whether used in brick, block, stone or concrete walls.
A feat of technology and engineering, Thor Helical remedial wall ties from Twistfix benefit from twin-thread longitudinal blades with a reactive interface angle, allowing and extremely accurate self-tapping penetrative path to be driven into the masonry element. Each wall tie has a circumscribed diameter of 9mm and is extremely resistant to corrosion.
The helix consistency and driving configuration aspects of Thor Helical wall ties are patented. Traditional ties involve clamping the wire at one end while the other is turned, developing a helix with a varying pitch across its length, Thor helical ties use advanced twisting die technology to control this pitch precisely, forming tightly-mating threads that guarantee superior interlock performance.
At the driving end, the patented arrangement (Pat GB2439633) guarantees safe, controlled installation at close quarters and low cost tooling that allows the operator to keep both hands on the drill throughout, making it easier during insertion.
Helical wall ties have been used for more than 25 years and have been subject to intensive independent testing programs. As recommended in B.R.E. Digest 329 (Table 5) as being “suitable for use in all remedial situations”, irrespective of the buildings substrate or its fire performance criteria, the ties represent an engineered upgrade on earlier designs and are CE marked to be reliable in all types of masonry.
The interlock anchorage of the wall tie does not exert expansive stress or rely on adhesion, continuing to provide its support throughout fire and temperature extremes without being affected. In cross-sectional profile, the tie reveals a wide portion which is there to maximise grip and a narrow portion responsible for accommodating differential movement in any and all directions. Migration of water across cavity is prevented by the deep, continuous helical troughs.
When under load, these helical troughs impart an accumulative cone of stress at tangential angles to the helix; this means that the load is evenly spread across the length of the tie.
The 3 Steps
DRILL a small pilot hole using a light percussive hammer drill. Make sure to stop the rotation of the drill before drilling the remote wall layer to prevent whipping.
Using a lightweight roto-hammer drill and SDS support tool, DRIVE the tie into the masonry.
Once the took recesses the tie beneath the wall face, FINISH the job by disguising the entry bore with suitable filler.
Cracks in masonry walls are a common structural defect and, upon being noticed, should be immediately remedied to avoid the problem worsening. So, how do they develop and how do i get rid of them?
The masonry materials of your property can only tolerate a slight amount of movement and there are many factors that can cause this movement. Variations in moisture content of the ground and the masonry itself, fluctuations in temperature and chemical reaction are common causes though vibration from living near to busy roads or railways can cause the issue.
The cracks are most likely to develop in corners or at window or door openings because it is at these points that the masonry is most stressed and least restrained. Some of the movements that cause the cracks are permanent but some are cyclic and can be reversed.
This is notoriously difficult for the untrained and can only really be achieved by observing and monitoring the cracks over a period of time to determine if they are active (increasing in size), passive (not increasing in size) or cyclic (opening and closing seasonally). Of course, you don’t want to spend all this time observing as the problem will be getting worse all the time! It’s best to call in the experts who can do a proper survey.
How do I repair the cracks?
Passive and cyclic cracks of less than 5mm in width can be easily repaired with simple brick stitching, a technique that will improve the masonry flexural and tensile strength, allowing it to tolerate these small movements. Active cracks that have exceeded 5mm in length need looking at by a structural engineer. Used alone, a masonry crack stitch system of repair is not reliable enough to solve active crack problems and will require further specifications.
Brick stitching involves bonding shaped, twisted stainless steel rods into walls at regular intervals, much like the stitching done with a needle and thread in fabric. Once installed, the rods cause the cracked wall to behave as an integral, reinforced and non-fractured unit. Stitching rods have a helical configuration which physically interlocks with bonding agent; this gives them a strongly resilient torsional quality, causing them to act like a spring and allow wall movements without cracking and other brittle failure.
It’s a simple and straightforward process. After cutting a horizontal channel into the masonry, preferably at the bed joint to allow for easier disguising of the repair later on, the slots are flushed with clean water to remove loose material and reduce the porosity if the brickwork, then filled with WHO 60 cementitious grout. Don’t forget to leave room for repointing and matching.
The high-performance, shrink-compensated bonding agent is then ready to have the stitching bars encapsulated within, leaving 500mm on either side of the crack dispersing loads evenly throughout the structure of the wall. Make good to disguise the slot and the job’s done.
Can I use resin to bond helical bars?
This would generally be discouraged as resin does not bear shear forces very well when perpendicular to the rod so unless the load potential on the helical bars was totally axial (parallel to the helical rods) then it’s not a good idea. Any potential for cross-plane movement requires high quality cementitious grout.
Our video can help you even further with cracked masonry issues. Don't forget that a major cause of stress in masonry is water, which expands by 9% when it freezes and makes cracks worse so sealing them as soon as possible is essential.
The roof, the roof, the roof is on fire! Oh, it’s alright actually — the rain will put it out. You might not be making hay while the sun shines but you SHOULD be sorting roofs out ready for the next nasty turn in the weather. Get insulated perfectly — use our insulation fixings for the very best, most reliable and strongest support.
These expertly-engineered fixings are rapidly taking the place of the old standard 6mm inskew-type fixings, which are limited in their ability to cope with greater bending moments as insulation materials became increasingly thicker. The robust Super-7 upgrades have been designed by W. H. Ollis, the original designer of the Helifix Inskew over 30 years ago. Thor Helical Super-7 Warm Roof Batten Fixings have been available in the UK for more than 13 years and are sold through Ancon Building Products and Twistfix; features and benefits of these superior Warm Roof Batten Fixings include:
Versatility – A patented alignment jig ensures perfect nailing through a wide range of insulation thicknesses supplied by popular brands including Celotex, Kingspan and Eco-Therm, ensuring a secure fix into the centre of the rafter every time
Environmental Awareness – A building installed with warm roofing will use substantially less energy than before, reducing carbon footprint
Cost-effectiveness – Designer W. H. Ollis mentions the ‘dramatic reduction in costs’ experienced when using stiffer Thor Helical fasteners due to the fact that less nails are necessary to strongly resist sliding loads. An insulated building, requiring much less power to heat properly, also means lower energy bills.
Rigorous Testing – The Thor Helical system has been independently tested to adhere strictly to the technical requirements of the NHBC (when used with Helicalc, a unique, free online software approved by the BRE and used to accurately calculate necessary sizes and quantities for specific projects) along with appropriate safety factors, Eurocodes and BS standards.
These robust insulation fixings are designed to improve substantially on galvanised Suretwist Big Twist fixings and, once again, deliver a wide range of useful advantages. Providing superior protection when professionally installed, our Insofast 18 stainless steel flat roof fixings:
- Are available in five sizes - our 245mm length was launched recently and its extended size allows it to be safely and successfully used with insulated ply decking composite with a thickness of up to a generous 210mm
- Feature a helical shank topped with a dome-strengthened head
- Work perfectly with OSB composite or insulated plywood
- Are fabricated from stainless steel, a metal which, compared to standard mild steel Suretwist fixings with zinc plating, deliver a reduction in cold bridging of a massive 80% - this is due to a combination of stainless steel’s low conductivity (four times less than ordinary galvanised carbon steel) and an ultra-low engineered CSA of just 9mm²
- Protect strongly against interstitial condensation and corrosion
- Save around 80% in cold bridging potential and reduce nail costs
Help from the Experts...
At Twistfix, there isn’t much we don't know about damp. In fact, we are pretty sure we know all there is to know about this pesky problem and, if you're reading this, then chances are you have come into unwelcome contact with it and need some help. Or perhaps you are one of the ‘be prepared’ types and want to avoid the problem before it happens. In any case, you're going to need our how-to guide on damp proofing walls, the Twistfix way.
Rising damp, the inexorable and persistent movement of groundwater upwards through permeable masonry, that is to say, walls. Water is funny stuff with many odd properties (including expanding as it freezes, unlike all other liquids) and one of these is capillarity, an electrochemical process in which water molecules are so attracted to the mineral surface that they overcome gravity. The result: damp walls leading to all sorts of other issues with the structure and the growth of moulds that are extremely harmful to human health.
A Damp Proof Course, or DPC for short. There are two types: one is a barrier impervious to water which is usually laid directly along bed joints during building construction. This is complemented by the remedial chemical DPC, which can be used successfully in a retrofit application by trade specialists and other competent structural workers and DIYers.
Usually, damp proofing chemical product is applied along the base of affected walls, lining the pores though not forming an impervious physical barrier. The aforementioned tendency of water molecules to be attracted to masonry is prevented as the chemical neutralises the charge attraction of the masonry pores.
The chemical DPC system chosen should be specifically designed for introduction to mortar joints, as it is the mortar that offers a continuous passage through which water can rise; DPC introduced into single bri9ck or block units will not prevent this rising. A height of at least 150mm above external ground level and beneath ground floor joists internally is required by BS 6576:2005: as close as possible to the floor is acceptable if the joists are solid. Incompatibility issues require the services of a professional and our trained staff are always available to help out.
At 100-120mm intervals, holes are drilled into the mortar in preparation for DPC cream to be dispensed. Migrating fully and rapidly, the cream will penetrate deeply and create the damp proof course. Any additional injection holes require vertical drilling, following a zigzag pattern through the mortar-line up to a height of one metre. The holes should then be injected with DPC cream, forming the vertical DPC that will effectively prevent damp transmission from any abutting wall.
High pressure injection fluids have been superseded by more effective DPC technology, readily available from Twistfix. The thickening agents relied upon by older creams are no longer required to turn the product into a workable mixture with the right viscosity; our Damp-Cure DPC, with its silane.siloxane formula, is thickened purely by emulsification. This means that the remarkable cream is 100% active, compared to the previous generation of DPC’s which boasted a pitiful 60% active ingredient content at best and sometimes as low as 10%.
The Finishing Touch
Groundwater that has risen through masonry pores will have left nitrates and chlorides behind. These salts are hygroscopic, which means they can absorb moisture from the air around (a quality that increases with humidity). Even when the water source has been eliminated, the absorbed salts will continue to attract airborne water vapour, meaning that damp continues to be an issue even after the DPC installation. Replastering the wall after the job is complete is therefore not only an aesthetic issue but an integral part of the process; indeed, replacement of wall plaster after the installation of a DPC is a requirement of BS 6576:2005 (the Code of Practice for Installation of Chemical Damp Proof Courses).
Seeing is Believing
We have put together a video with lots of details and information about damp proofing walls and you can watch it. Defeat Damp the Twistfix Way!
Any repair, renovation or construction project first requires extensive analysis in order to ensure the correct tools and products are used. Twistfix supply a comprehensive selection of analytic tools and instruments that are guaranteed to provide accurate results on most environmental factors.
The Protimeter Mini is a digital moisture meter with such a superlative level of quality that it has become the best-selling product of its type in the UK. As the first selection of many surveyors and damp proofing professionals, the Protimeter Mini is expertly-designed to accurately measure the levels of moisture before displaying this essential information to the user via a clear, concise LED display which also features colour-coding. In addition to this display numerical scale effectively reads the moisture content of wood, showing this as a percentage figure that compares with a relative moisture equivalent for other materials such as masonry and brick walls.
With an innovative optical system that boasts superior levels of precision, the Twistfix Rigid Boroscope allows simple, rapid inspection of ties buried within cavity walls. The product also effective for viewing in other areas where access is restricted and this quality is further enhanced with the addition of a powerful halogen lamp. The unit is supplied with a rechargeable battery and charger, making it one of the most cost-effective and essential choices available within our extensive surveying selection.
Particularly suited to the quality control of cavity wall tie installations and pre-contract product suitability tests, the Twistfix Wall Tie Testing Kit is one of our most popular products. The kit comprises a high quality tension tester engineered with a 3.5kN capacity guage and an adaptor key specifically designed for testing Twistfix helical ties. Utilising a load-cell in conjunction with a mechanical pulling mechanism, this tensile testing kit accurately measures tension forces and features an integral bridging unit.
Damp comes in many forms and, though probably the most well-known, rising damp is thankfully the least common. When rising damp occurs, it is essential that the problem is corrected as soon as possible.
Moisture, particularly groundwater, will naturally and gradually seep into porous masonry, rising into the wall via capillary action. Water becomes water vapour as moisture evaporates from the wall in a continuous wetting and drying cycle. As it evaporates, chloride and nitrates (hygroscopic salts) dissolved within it are left behind on the wall surface, building up and having potential to draw in further moisture from the atmosphere. It is generally thought that moisture will rise to a height of about 1metre before evaporating and leaving behind a salt band. The deposited salts and a clearly visible tidemark of moisture are the two most obvious signs that rising damp is present within a wall.
Rising damp is most commonly found in buildings to which a damp proof course has not been applied. It can also occur in buildings where a damp course is present but has failed. There are many possible causes of DPC failure but 'bridging' is the most common reason for a damp proof course to stop functioning. The simplest cure for damp caused by bridging is to remove the bridge and allow the DPC to function correctly. This may involve reducing external ground levels and/ or clearing blockages from cavities. Where this is not possible or practical a new DPC can be injected. Removing the salts is essential to break the cycle in which more and more moisture is drawn to the masonry, exacerbating the damage. To repair this insidious form of damp, it is important to select damp proofing products of the highest quality to be utilised by a competent person.
The Twistfix Rising Damp Kit contains everything required to effectively damp proof 30m of single-leaf wall or 15m of 9" walls. At the core of the kit is three litres of high-quality DPC injection cream and five litres of waterproof plaster additive. Formulated with the use of an innovative emulsification process and without the use of thickening agents, the 100% active silicone-based damp proofing cream is designed to rapidly migrate throughout the pores of damp masonry, quickly forming a complete chemical damp proof course. The plaster additive, when diluted and added to the render mix, acts as a salt-inhibitor to restrict the movement of salts as the moisture evaporates and the wall dries out.
Along with the damp proofing cream and plaster additive, the Twistfix Rising Damp kit also contains two professional SDS drill bits, an injection extension tube and a heavy-duty caulking gun. To ensure the product is used safely, a pair of protective gloves is also included within this comprehensive rising damp treatment kit.
For information on rising damp treatment available from Twistfix, please contact our expert technical team.
Cracked masonry is one of the most common structural defects. The problem is particularly common in older buildings and, to avoid further damage and the possible collapse of the structure, any cracks must be quickly repaired to restore the safety and structural integrity of the property. Helical crack stitching bars are the best way to repair cracked masonry, quickly providing the much-needed support required to give the building a continued service life.
The process of repairing cracked masonry using helical crack stitching bars is simple yet delicate and must be carried out by trained and trusted contractors to ensure the job is completed to a safe and professional level. Helical bars are retrofitted directly into the masonry, reconnecting any cracked areas which are then grouted over to form a tight, lasting seal. The innovative helix shape of each bar is designed to enhance flexural and tensile strength within the masonry, fully redistributing load forces along the full length of each bar. This increases the stability of the structure and guarantees that any further sagging, movement or cracking of the walls will not occur.
Twistfix Helical Crack Stitching Bars are manufactured in the UK to patented engineering tolerances. Rendered in high-tensile 304-grade stainless steel to provide the ultimate in strength and corrosion-resistance, the products have been rigorously tested in order to ensure they meet and exceed every official specification, including conditions for CE Marking. The bars are available in a choice of three sizes and in packs of ten; installation will require the use of masonry repair grout along with accessories, all of which are also available from Twistfix separately or as part of a comprehensive kit. Look out for a news article detailing our masonry repair and crack stitching kits soon.
Our helical crack stitching bars form an integral part of our masonry repair systems and solutions. For more information on our comprehensive range of products, including remedial wall ties, please contact our dedicated technical and customer service team.
Everybody knows just how dangerous fire can be and how easily it can get out of hand; some of us have been unfortunate to experience the effects personally. Fire’s capability to get out of control is legendary and a simple stray spark can quickly grow from nothing to an uncontrollable inferno. It makes sense to take as many precautions as you can against disaster and fire retardant paints and coatings are an excellent first step.
It’s a quick, easy and inexpensive job, that might just save your home or even your life, to apply our quality fireproof varnish to wood and any other timber derivatives while you’re at it. In just three simple, clearly-defined steps, you can provide Class 0 Fire Rated Protection to your property. Here come the tech specs…
- ThermoGuard Fire Retardant Varnish comes as a kit comprising activator, top coat and the all important intumescent varnish base
- Each kit contains sufficient product to coat around twenty square metres
- If there is a fire, the base expands dramatically in response, forming a tough, fire-resistant carbon char to insulate the wood from the worst of the flames and heat - smoke is held back too and this is all confirmed with stringent EU testing
- Final topcoat gives a durable and decorative finish so it’s great to use for internal woodwork or external cladding; a totally clear formulation lets the substrate shine through with its natural glory but with infinitely enhanced peace of mind, it's a combination that’s difficult to duplicate
- Choose from satin or matt finish; both offer UV protection on top of the fire protection so nothing is going to stand in your way, whatever the British weather decides to chuck at us next!
Choosing a professional product like this from a reliable supplier like ourselves is the winning combination that will put you, your family and your property in a safer place. Our product range will always reflect quality, diversity of choice and competitive pricing; our fire retardant varnish is no exception so why not check out our attractive price discount...?