Repairs made on a Heritage Sydney Sandstone Front Fence. 20 years old and still looking great!
As a result of drilling and silicone injection having been previously used on the above Edwardian brick heritage property, located in the Melbourne suburb of Flemington, the failure of the process is evident in that, rising damp has still occurred despite the previous owner’s intent in trying to fix the issue.
Despite the effort in trying to stop the moisture, the buildings previous owner was only trying to do what was right. The fact is that silicone injection seldomly works. It is really only for walls over 2 foot thick. It is certainly not for a heritage double brick structure. Discolouration, as seen above, affects both mortars joint and brick alike; hastening deterioration of both.
By using a physical barrier instead, this wouldn’t have occurred. Rising damp is a very hard thing to prevent altogether. In all actuality, every masonry structure will encounter some form of moisture transferral from the clay sub-found material. In the case that physical barriers are installed, the decay of mortar and brick is slowed dramatically. By also increasing airflow under the floor, you are also providing a good natural method of easing rising damp.
Contact melbournebrickrepair.com for further details on how to prevent rising damp.
Over the years, the construction methods regarding rising damp have changed. With new ways of attempting to prevent the rise of dampness from footings and surrounding sub-foundations which are generally comprised of clay, there has also been an increase in the use of chemical injection systems. These systems have gained in popularity due to the inherent belief that plastic is non-absorptive. We believe that the injection system, whilst being beneficial in certain circumstances, can not be looked at as the single and best remedy. We will now break down the reasoning behind why both silicone and polyurethane inject systems that are utilised to counter rising damp are liable to not work.
As a result of drilling at regular intervals, the chemical injection systems use the basis that the brick will ‘absorb’ and disperse the silicone or polyurethane injection applied to try to prevent rising damp. Not only does this depend on the contractor, how well they drill and how much injectable they use, the nominal absorption of various brick will vary due to composition, age and even colour. Concrete blocks, natural stone and clay brick all have differing absorption rates. You can see from the photo above, the ‘cover-up’ bandaid approach does not work with the mortar being soft and still falling out despite the attempt to mask the symptoms of rising damp.
2. Plastic attracts moisture
So you’ve thought to inject silicone or a polyurethane into the masonry fabric of your building. Did you know that once you have injected plastic into what is otherwise a very porous and freely evaporative masonry matrix, you are actually going to harbour moisture in the bricks located in the injected region?! We have found that this will deteriorate your brick faster and often doesn’t stop the moisture tracking its way through both the mortar joint and the masonry unit.
3. Slowing of the Moisture Cycle
The mere fact that you have injected plastics into what was previously a very breathable and porous masonry structure, you are increasing the moisture retention in those areas.
Test it for yourself; If you saturate two clay bricks in water, coat one in cling wrap and not the other, and then place both into the sun, which do you think will dry quicker?
Of course, the brick with plastic will not dry at all. By eliminating the porosity and the rate of evaporation, you are hastening the corrosion caused by being constantly waterlogged…
Silicone and Polyurethane chemical injection systems are somewhat useful in thickened masonry walls with optimal thickness of around 300-400mm. This is due to the physical difficulty of retrofitting a physical barrier in order to prevent rising damp. To install a physical barrier at this depth is very slow going and is generally quite expensive due to it being labour intensive. But this does not mean that you shouldn’t spend the extra money to do something properly! It is against the basic principles of economics to pay a little for a lot… be aware of the quick fix that is cheap!
Chemical injection systems utilised on single skin brick cladding should not be used! Even on double brick structures which are generally only just over 200mm in thickness with a cavity or empty void in between… The mind boggles on how some contractors would think that this would work!
Physical barriers such as lead and slate were used in traditional damp coursing. These methods were very successful at preventing rising damp. Both materials were largely long-serving due to their individual material impermeability characteristics. They prevented the physical movement of moisture up the wall whilst maintaining their physical state.
Modern equivalents are generally reinforced polyurethane and other flashing material. These are just as effective and require less financial outlay than utilising lead and slate. The main benefit beside stopping the vertical movement of moisture is allowing the masonry to evaporate. This enables the brick, block and stone to remain as dry as possible which is the goal in trying to prevent dampness and the odours associated with saturated masonry.
Despite the thousands of dollars spent, the previous owner didn’t stop rising damp nor did they prevent the other aspect of moisture sub-footing conditions, subsidence. Underpinning is also a follow-on issue with rising damp.
By spending more, and being wise in your choice of contractor, you will receive more… Throwing good money after bad is never beneficial. Fix rising damp once and for all with melbournebrickrepair.com. The Physical Damp Course Specialist.
Is your house cracking up? Made it through winter and now you want to get the house airtight and weatherproof? You may need crack injection and/ or brick stitching.
First, the mortar material in between the bricks should be removed. This will provide longer serving results for the repair. Next, the joints are lined with the steel reinforcement. These elements are either galvanised or stainless steel.
With the brick stitches in, next is the final tamp point.
Want to clean lichen from your roof tiles, brick or stone walls? There are several methods which you can use to help remove the unsightly outbreaks.
The Dry Scrape
By taking the time to remove lichen this way, you can also improve the surface of the stone, tile, brick, or block that is harboring it. Lichen are a mixture of fungus and mould, created by spores and moisture. They can harbor moisture helping to breakdown the stone or masonry surface underneath.
By taking a dull object such as a straight piece of softwood, you can physically dislodge the lichen from the surface of the substrate. The following video shows the movement albeit has a chisel being dragged instead of a piece of timber. The stone in this case was also bluestone which isn’t easily marked. Caution should always be used with soft stone such as slate, marble, sandstone and limestone.
If you have an ornate statue or architectural feature such as an intricate carving, you will want to use other methods in conjunction with a very soft, dry scrape.
Wrapping a statue up in cling wrap for 3-4 days will help to soften dirt, mould and fungus that may have hardened. After the pollutants have softened, remove the ‘poultice’ and commence using a soft dry scrape method as shown above.
Spraying chemicals has its appeal but it also has it’s drawbacks. If not diluted or used properly the typical ammonium-based sprays can cause damage or not work at all.
Wet and Forget
Use a garden sprayer to thoroughly saturate the lichen with a solution of 1 part Wet & Forget Outdoor and 5 parts water. Wait 15 minutes, and spray a second time. This will allow the Wet & Forget Outdoor to penetrate the lichen’s 2 layers. It is best to spray lichen on a day that is not too sunny, to prevent rapid evaporation and to allow Wet & Forget more time to work. Read more…
Visit vicrestorations.com for further information and to make contact.
When comparing traditional ribbon pointing as opposed to brick tuckpointing there are several differentiating factors.
As you can see from the above photo, the heavy oxide mix used on brick tuckpointing (top courses) can actually cause issues if not installed correctly. Mortar, often used in only one colour, is used to smear over the original bedding mortar which is visable where the red coloured mortar has fallen off. This is due to the smear coat method only being several millimetres thick or possibly too brittle to start with. In the instance above, this is definitely the case.
Another issue is that due to oxides’ cementitious effect on the mortar matrix, the mix can often be quite destructive to the 80-100 year old brick. Mortar, as also evident above, is smeared over the brick arris; partially covering the face. In tension, this can snap corners off and even break bricks clean in half–especially old, soft brick.
The biggest comparison, besides appearance, is that the traditional ribbon technique will protect the brick, whilst at the same time, provide depth and definition to the masonry facade. Standard tuckpoint can last quite a while but as opposed to the deeper ribbon pointing, the facade will age better and can last a lot longer.