General FAQs

A broad knife, sanding paper, sanding block, Filler/Flexible Filler/Expanding Foam (depending on the job)

Large or small, Indoor or Outdoor (every environment can be different)

This is all going to depend on how big the hole you are filling is and what you are using. You will also need to consider whether the filler you are using allows you to fill a deep/large hole in a single go, or if you will need to build it up in layers.

Almost any type of hole can be filled in any surface as long as the correct preparation, choice of product and filling is carried out.
A textured finish is possible however you will need to create the right surface appearance to match the surrounding surface, this may even require some specialist techniques to achieve this

Remove any flaky/dusty/rotten material, sand back the edges slightly to ensure there is no lifted surface at the edges.
Thoroughly blow out the hole, so it is free of dust and ensure it is dry.

Work the filler into the hole ensuring that you fill the back of the hole first, this ensures that you have no gaps sitting in behind the filler. You should always fill to just above the surrounding area so that you have a surface to sand back to. With some fillers you might need to build the depth of the filler up in layers, allowing it to cure between fills.

This all depends on what product you are using and the temperature of the area you are working in and the temperature of the surface you are filling.
For an epoxy filler (Gorilla Bog), the time may be as short 20 minutes until fully cured.
For a non-flexible filler (Patching Compound), the time will vary but may be as short, for some types, as 5-15 minutes before you can sand while for others it may be several hours.
For a flexible filler (Gorilla Pro Gaps range), these are not really designed to be sanded but rather just tooled off to a smooth finish, some of these you can paint after as little as 10 minutes.

As long as you haven’t tried to fill the hole with something like silicone, it is possible to paint over repairs.

Use a 80-120 grade sandpaper and a sanding block where possible as this will give an even pressure over the area you are trying to sand, especially if on a flat surface.

This is based on the environment, but if you have chosen the correct product for the environment, prepared the hole, filled it and coated it, then you could expect the repair to be permanent.

If you are filling narrow gaps (between two surfaces) you are best to generally use a latex-based acrylic filler (Gorilla Pro Gaps Multipurpose) as this can be quickly smoothed off with a painter’s broad knife or silicone finishing tool (Gorilla Sealant Finishing & Removal Kit).

If you are filling holes in plasterboard or timber you really require a ‘static filler’ (Gorilla Bog or Patching Compound) that does not move, so that you get a good flat surface to paint over.

This is really up to you, if you think it is unsightly, and you are repainting a surface. Then doing the filling and finishing will give you a far better finish.

An expanding foam will fill larger gaps, but the you need to consider the following:

To use a foam, the gap really needs to be over 15mm in width, but you will need to think about how much you are putting in as there are often large open spaces behind the area and it is generally not advisable to just keep adding foam as the gap in behind was created for a reason by the original builder.
The expanding foam will need to be trimmed back below the top surface of the gap/crack (as the finish of the cut back expanding foam is not visually nice)
If outdoors, then the expanding foam is not UV stable so will deteriorate over time.

Cutting back the expanding foam means that the outer surface will no longer stop water coming through.

All expanding foams will, after being trimmed back, need a filler coating over it to make it look better but also to protect it.

Yes provided the filler allows you too, this is why the choice of using a silicone based product should be avoided unless you know that you will never be wanting to paint over that area.

Make sure any loose material is removed, and the gap/hole is clean, dry and dust free.

Work the filler into the hole ensuring that you fill the back of the hole first, this ensures that you have no gaps sitting in behind the filler. You should always fill to just above the surrounding area so that you have a surface to sand back to. With some fillers you might need to build the depth of the filler up in layers, allowing it to cure between fills.

This all depends on what product you are using and the temperature of the area you are working in and the temperature of the surface you are filling.
For an epoxy filler (Gorilla Bog), the time may be as short 20 minutes until fully cured.
For a non-flexible filler (Patching Compound), the time will vary but may be as short, for some types, as 5-15 minutes before you can sand while for others it may be several hours.
For a flexible filler (Gorilla Pro Gaps range), these are not really designed to be sanded but rather just tooled off to a smooth finish, some of these you can paint after as little as 10 minutes.

Yes, but you need to understand the environment that you are working in and the conditions that the filler will have to endure over its life. It may be that you need to make a more careful selection of the type of filler when working outdoors than you may have to indoors.

Indoors generally only when you redecorate or make alterations.

Outdoors, will depend on the type/location of the gap that you are filling, but generally, expect a repair to last a number of years. Some of this will depend on your selection of a filler and how much movement it is subject to.

Filling gaps has several advantages to help with energy efficiency:

• Prevents unwanted air flow or drafts outdoors.
• Can stop water or water vapour from coming inside.
• If you are filling gaps in areas where insulation cannot be inserted (and there are small spaces), if you use expanding foam then you will improve the overall energy efficiency of the space provided you fill to a depth as outlined in the technical data sheet for Gorilla Pro Expanding Foam.

Interior, either a latex based acrylic filler like Gorilla Pro Gaps Multipurpose, Gorilla Pro Gaps All in One or Gorilla FixALL Crystal.

Outdoors, Gorilla MS Sealant (if you want to possibly paint over the joint), or a quality silicone like Gorilla Roof & Gutter or Gorilla General Purpose if you never want to paint over the sealant.

This is really up to you, if you think it is unsightly, or the previously sealed joint is allowing a draft or water through the joint and you are repainting a surface.

Yes you can, but understand that you will never be able to paint over the sealant.

As long as you haven’t tried to fill the hole with something like silicone, it is possible to paint over most repairs.

The old sealant needs to be removed and the surface needs to be clean, dry and dust free.

Here is a video that steps you through the process. Click here.

Having the right product and tools is important, we suggest a neutral cure, mould resistant silicone, we suggest Gorilla Bathroom & Kitchen Silicone. Unless you want to paint the surface, then go for an MS based product like Gorilla MS Sealant.

Here is a video that steps you through the process. Click here.

This all depends on what product you are using and the temperature of in the area you are working along with the temperature of the surface you are sealing.

For a flexible filler (Gorilla Pro Gaps range), these are not really designed to be sanded but rather just tooled off to a smooth finish, some of these you can paint after as little as 10 minutes.

Silicones will vary on the depth of the joint and the surrounding temperature, silicones will skin meaning it is waterproof immediately but will take 24 hours to full cure.

MS based will vary on the depth of the joint and the surrounding temperature, you should be able to paint an hour after application

Yes, but you need to understand the environment that you are working in and the conditions that the sealant will have to endure over its life. It may be that you need to make a more careful selection of the type of sealant when working outdoors than you may have to indoors.

Indoors generally only when you redecorate or make alterations.

Outdoors, will depend on the type/location of the gap that you are sealing, but generally, expect a repair to last a number of years. Some of this will depend on your selection of a sealant and how much movement it is subject to.

Sealing gaps has several advantages to help with energy efficiency:

• Prevents unwanted air flow or drafts.
• If outdoors, it can stop water or water vapour from coming inside.
• If you are sealing gaps in areas where insulation cannot be inserted (and there are small spaces), if you use expanding foam then you will improve the overall energy efficiency of the space provided you fill to a depth as outlined in the technical data sheet for Gorilla Pro Expanding Foam.

Tape is a backing film, most often made of either paper, cloth, or some type of plastic type material (Polyethylene, Vinyl, PVC, Polypropylene).
An adhesive is what causes the ‘backing film’ to stick to a surface.
Tape is a combination of a ‘backing film’ and an ‘adhesive’.

Pressure Sensitive Adhesive Tapes are a flexible and sticky adhesive tape that will adhere to a substrate by the amount of pressure used. This is different from just a normal adhesive tape where you put it in place and it holds, a pressure-sensitive tape requires physical pressure to the surface to ensure it bonds. If a tape requires heat or a special primer to make it stick, then this is not a pressure-sensitive tape.

There are many different types of adhesives, some are more common than others:

• Common – Water-based (acrylic), polyurethanes, super glues, solvent based
• Specialist – Hybrid Polymers (MS), Butyl, Bituminous, Silicone

Adhesives are designed for particular surfaces, while some are designed to work on a wide range of surfaces, others may only be good for very few surfaces. This is why it is important to understand the surface you are sticking to, the job you are asking the tape to do, and the environment that the adhesive will be working in.

As there are many different types of adhesive the drying times for adhesives also vary a lot. Depending on the adhesive the time range to cure could be from a few seconds to many hours. This is also why it is important to understand the surface you are putting it on to, and what you are wanting trying to achieve and what the environment is.

It is best to refer to the specific technical data sheet for the product you chose to get this answer.

It is often very difficult to remove all traces of an adhesive from a porous surface such as wood concrete/stone due to the adhesive getting into the pores of the material.

In most situations uncured adhesives can be removed with Gorilla Trade Tough Wipes, ensure you act fast before the product cures

Many adhesives can be removed from a surface however this is dependent on

• The type of surface
• The surface finish

You may require a particular ‘remover’ for that adhesive type to do the job. It is best to discuss this with the adhesive supplier. It is never a good idea to just try different products to remove an adhesive because you may use something that will cause the adhesive to set even harder to the surface. It is always recommended that you try any product used as a ‘remover’ on a small unobtrusive area first to ensure that you do not damage delicate surfaces.

If this is the adhesive from a tape then Yes, however, you will very likely require an ‘adhesive label remover to do this successfully. Even more so if the tape has been in place for a period of time.

Paper-backed, Cloth, Vinyl (PVC), Acrylic, Polypropylene (PP), Polyethylene (PE), Teflon (PTFE), Aluminum Foil, Bituminous, Butyl, Amalgamated Rubbers

Yes, although you need to choose the correct tape for the surface you are putting it on to and the environment.

Start by understanding the surface you are putting it on to, and what you are wanting to achieve, and what the environment is. Some tapes work better on some surfaces than others, while others, if the surface is too cold/hot require some preparation to help them stick as they are designed to.

Yes, many can as both the backing surface and the adhesive are both waterproof and UV resistant, but again it comes down to understanding the surface you are putting it on to, and what you are wanting to achieve, and what the environment is.

This largely depends on what you are trying to achieve. Often while the ‘backing’ tape will last for a long period of time the adhesive itself may change over time. Exposure to the elements does affect how long the backing tape will last.

As a rule of thumb:

• Most decorator’s tapes that you buy will state on the packaging the length of time that you can apply them to a surface, and they can be removed without leaving any adhesive residue. Commonly, these are a form of paper-backed tape. There are also Vinyl-backed decorator’s tapes that may be more suitable for outdoor use but again check how long you want the tape to last before removing it, without leaving any adhesive residue.
• Some Vinyl/Polyethylene backed tapes can last for up to 6 months but you need to choose these carefully and check with your retailer for specifics.
• Aluminum/Bituminous/Butyl backed tapes, if used in the correct environment can be used for many years.

These products provide an envelope treatment in accordance with NZS3602 Timber & Wood Based Products Used in Building “Section 2.3.5 Supplementary Treatments” for H3.1, H3.2, H4, H5 Timber Treatments. This provides protection to cut, notched, scarfed and ripped timber and ply to that the worked timber complies with the NZ Building Code. Provides protection to the treated surface against UV degradation, water ingress, mould & fungal decay and insects attacking the treated timber.

No, it is solvent based.

They both have an equal strength, they just do it in a slightly different way, but the end result that the user is after is identical.

The difference main differences between the Metalex products are

• Metalex Timber Preservative (Concentrated, Ready to Use, Aerosol) is an end/envelope treatment only, to preserve the treatment envelope only. And as such can be painted over following the required drying time (time for the solvent carrier to dissipate). Ideal for medium and softer timbers.
• Metalex Wood Protector is a final coating and cannot be painted over, as it will not allow the paint to adhere to the fibre’s underneath. It preserves the natural look of the timber while making it impervious to moisture penetration and UV. Ideal for hardwoods and timber with very close grain.

Light Solvent such as Turpentine or similar.

• Metalex Timber Preservative (concentrate) is mixed at a ratio of 3 : 2 for every 500ml of Metalex Timber Preservative ADD 750ml of Mineral Turpentine
• Metalex Timber Preservative (Ready to Use, Aerosol) is ready to use
• Metalex Wood Protector is ‘Ready to Use’

Yes – Metalex Timber Preservative can be used to add durability to untreated timbers, however, this is not the same as using treated timber products in the first instance. It should also be noted that if you are using it on plywood, then the product will not penetrate the ‘glue line’ between the layers of the plywood.

No, Metalex Timber Preservative(s) is an end/envelope treatment only, to preserve the treatment envelope only. It is not a treatment in its own right. This is clearly stated in NZ3204 of the NZ Building Code. However, is still able to be used as an end treatment for new timbers used in H3.1, H3.2, H4, H5 remedial works.

Yes, however there are some important things to consider.

Metalex Timber Preservative(s) and Metalex Ready To Use are solvent based, therefore before an acrylic base can be applied over it you need to ensure that the solvent has evaporated out of the applied timber.

• Acrylic based coating – a period of 10 days (Ca. 20°C, 65% R.H.)
• Oil based enamel coating – a period of 3 days (Ca. 20°C, 65% R.H.)

With any wood product (Plywood or Solid Timber) you will get “draw” (to different extents) of the above products up the grain (end grain more so that side grain due to porosity of the timber grain).

As these products are solvent based, and as such may/will change the visual colour of the timber that has been exposed to the supplementary envelope treatment.

If you are going to clear coat the board/panel, you need to coat the full face of the board with the Metalex Timber Preservative or Metalex Ready To Use, so that the finish is consistent across the timber face.

If the final coating on the revel was to be a full colour, there is no need to coat the full face of the timber as the “draw” line would not be visible.

A simple way to see if your surface is ready is:

• When you apply the treatment to the timber also apply a treatment to a spare piece of timber.
• Before you put the finished coating on the good timber try it on the spare timber and see if there is a reaction.
• If there is, then there is still solvent in the timber and you need to wait longer.

If ever you come across new paint easily peeling off the old paint you can be nearly sure it will be because acrylic has been painted over enamel. There is a simple way to deal with this.

If painting acrylic over an enamel you need to make sure the surface is clean, then give it a light sand and then use an oil-based under coat before you apply the acrylic top coats.

Yes, it can – especially when diluted to 1 part Metalex to 5 parts solvent rather than the usual 2:3 ratio. Remember that the treated timber needs to then be left to “weather” for a period of at least 6 weeks to ensure that all of the Solvent carrier (used to carry the Copper Naphthenate salts into the timber) has evaporated from the timber.

Yes, Metalex Timber Preservative(s) or Metalex Ready To Use can be used with its insecticide values to eliminate the infestation of flying borer. If borer is pre-existing in the timber it will continue boring through the timber until it emerges and has to break out which will then cause it to die (however the Borer fly does not tend to eat on its way out. Treatment by the “Metalex” range of products will actively discourage Borer fly from settling on or laying their eggs in the treated timber.

Yes, it can in the Metalex Wood Cleaner formulation prior to the application of the Metalex Timber Preservative(s) and Metalex Ready To Use.

While there is an argument for just using the above Metalex products for this purpose, neither of these products will give you a clean timber surface free from “Black Mould” for the next stage of the process. Due to the copper in the Metalex Green this product will have a higher inhibitive effect against future mould growth than the clear version.

A pressure-free securing of threaded rods, studs, reinforcement bars, threaded collars, profiles etc into concrete, concrete blockwork, stone and masonry substrates.

Chemical cure, the product has a special nozzle that mixes the product when it is gunned out. The chemicals then react with one another to cure to create a strong lasting bond when mixed correctly.

SoudaFix is for heavy to medium applications. It has a C1 Seismic Rating, works on cracked and uncracked concrete and compiles to requirements in the NZ Building Code.
BoltFix is for medium to lightweight applications and only in uncracked concrete into concrete, concrete blockwork, stone and masonry substrates. It can be used on solid & hollow materials and is suitable for exterior applications.

If you are meaning, “can I use it to repair cracked concrete back to its uncracked/original strength”, then unfortunately No.

The anchor adhesive can be used to repair and fill cracked concrete, however while it will provide a strong hardwearing repair, this will not result in the cracked concrete having the same strength as it had before it was cracked.

The requirement is set out by the NZBC, Engineers and Building Authorities when they consider the anchor to be critical to function and if there is a possibility of endangerment to human life. 

NZS 3101 Concrete Standard (amendment 3) included requirements for all post-installed concrete anchors to be designed to European Design Standards (EOTA TR045) and European Test Standards (ETAG 001). The standards written in ETAG 001 set out the basis for using anchors in cracked and uncracked concrete. The scope of ETAG 001 states that C1 and C2 anchors should be specified  “when failure of anchorages made with these products would compromise the stability of the works, cause risk to human life and/or lead to considerable economic consequences.”

The difference between C1 and C2 is the size of the crack that the anchor will work in. C2 works in a bigger crack than C1.

• C1 anchors are tested for both shear and tension forces
• C2 anchors are tested for shear & tension forces & deformation (seismic) forces

C2 is always required where there is the possibility for endangerment to human life.

• Due to the seismicity of the regions across NZ Auckland and Northland are the only regions where C1 can be used.
• In other parts of the country C2 is always required where there is the possibility for endangerment to human life.

Even in other regions C1 will be often preferred over a standard BoltFix as it works in cracked concrete which a standard BoltFix type product will not.