Victorian solid brick walls-cement and sand or lime render on internal wall
Our Victorian end terraced house that we moved into in November last year had soaking damp walls which we removed (the plaster behind the wallpaper was crumbling off- it was that damp!). Inside, the two external walls downstairs (living and dining room) have been stripped back to brickwork and the house now feels dry after letting it breathe for 6 months. We’ve been told by the independent damp surveyor that the damp was most likely a very long term condensation problem (the previous owners lived there for 45 years..used a gas fire..poorly ventilated the house etc..)as there was no evidence of rising damp. Where its been stripped to brickwork, some bricks are crumbly and I think the wall needs some kind of render before plastering.
We’ve had a quote from a plasterer who said he will make good these walls using sand & cement with a water proof additive walls followed by two coats p. v.a + top coat of multifinish plaster to a smooth finish. The front of the house has been pebbledashed by the previous owner. My question is, will it be detrimental to use sand and cement rather than some kind of lime render to let the walls breathe? But I’m also thinking, can the house breathe anyway with the horrible pebbledash that is on the outside of the wall that needs to be internally rendered?
Or would it be best to drywall these external walls by adding battens? If this is the case, would the brickwork still need internal rendering (which kind?) before adding the battens since its crumbly?
Some advice would be much appreciated we are getting the replumbing done next month and need to figure our what to do with the walls!
Thanks a lot
5 Answers from MyBuilder Plasterers
Ilfracombe • Member since 23 Apr 2015 •
The moisture in older walls needs to be allowed to evaporate or “wick” away, ideally, both internally and externally. This can only be done with lime mortars and plasters.
The damp course in your wall is probably a layer of slate and is often rendered over, forming a bridge which allows the moisture to move up the walls behind the render. Waterproof materials will only keep moisture trapped in the walls, damaging brickwork over time and creating condensation problems.
Allowing this moisture out in one direction only is better than none at all, so the re-rendering of the exterior with lime mortar, while preferable, will probably have to wait if you haven’t budgeted for it. As the plaster indoors is already damaged, I would start there.
Suitable lime mortars and plasters contain no cement at all so check the products builders intend to use.
Hope this helps.
Answered 27th Apr 2015
MR D Barnett
Kent • Member since 31 Jan 2016 •
If the house is built using lime render should be applied in lime so it can breathe render should be 3 part sand to 1 hydraulic lime. Most internal damp is caused by internal render being gypsum plaster this is a big no no as it draws moisture in from external face hope this was helpful
Answered 16th Oct 2016
Neath • Member since 14 May 2015 •
Hi Good Morning I would agree with Guy he has given some good pratical advice with regards to moisture retention slate Membrane and bridging However there are many ways to stop damp and contamination to internal walls
#it is important to have the property surveyed correctly before making the most appropriate application and planning the best way forward with the problems you are having
I would also advise to look at the state of the external render as if you have a product on the wall which could be porous render breaking down hair line fractures within the sub strate, Any work you do inside to be frank you are wasting your money! Make good of the out side first
There are Membraine systems/ semiticous tanking Applications that can be done inside that will protect your internal walls, but that does not cure the problem as much as it is still there but does not effect you internal living ie your health decorating and so on. ……
I think its always a little unfair to comment on any contractor who is hands on been to your property etc my advise overall is to correctly have the works surveyed to determine the best way forward, and make sure your Builder includes this in his report, and establishes the reason why and how he is going to proceed to give you the solutions and any Guarantees etc etc…. hope this helps
Garry Reilly Plastercare
Answered 18th May 2015
C.J Systems Eco Thermal Design
Colchester • Member since 6 May 2015 •
I Would suggest External wall insulation system but would need to survey the project before i could advise you on the specifications to solve your problems
Answered 30th Jul 2015
Cheriton • Member since 22 Jul 2008 •
The second you paint over a lime based render you run it.
It should be allowed to breath.
The water can’t escape the wall due to the paint and so it is being drawn internally and ruining the internal plaster.
Pva should not be used if there is a chance of moisture. PVA is backwards compatible (much like wallpaper adhesive)
Lime based mortars are specialist and can be expensive. I wish you luck with how you proceed 😔😊
Answered 9th Jul 2020
Transforming an Interior Wall with Render
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“What colour shall we paint our walls?” After going to the paint supplier and looking at colours, you’re still not happy. You want to do something exciting with your walls: something that will transform the appearance of your room. What can you do? Have you considered applying render to your interior walls?
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Transforming an Interior Wall with Render
There is nothing new about render. Interior walls were rendered long before plasterboard was invented. Mud was the first material used to render interior walls. Cement came next, followed more recently by modern acrylic renders. Neglected as an interior wall treatment for decades, render has been rediscovered and thousands of Australian homeowners are transforming the appearance of their home interiors with render.
The difference between paint and render is that render allows you to add depth and texture to a wall. Professional rendering services often establish their reputations by offering unique textures or a range of stylish options. Some of the effects skilled renderers can achieve include:
- Mudbrick appearance using special trowelling methods and coloured render.
- Natural concrete render for a modern industrial or minimalist look.
- Rough textured render combined with vivid colour on a feature wall.
Renderers use trowels, rollers, sponges and other tools to apply render. Rendered walls can look like natural concrete, be painted a single colour or render can include subtle differences in texture and colour to create an antiqued appearance.
Until recently, render was typically a mixture of cement, sand and lime. It is an effective treatment, but takes a long time to dry (up to 28 days) and is not 100% waterproof. Today, most renderers use acrylic render, which is cement with added polymer. The polymer makes the render more flexible, adhesive and waterproof. Acrylic render also has the advantage of drying in only two days.
Render is commercially available and applying it can be a DIY project. However, it is not as easy as painting and texturing requires skill. Rendered walls are always feature walls because of their unique appearance. To be sure your rendered walls are features you and your guests will admire, get quotes from professional rendering services. Look at their portfolios and choose a service that provides the look you want to achieve. Let them do the work and you can sit back and admire the results for years to come.
You might also like: Render or Re-Paint My Interiors?, Getting Quotes for Rendering Jobs
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Plastering of brick walls, what is the price for work in Moscow?
The most common type of rough finishing work performed by the capital company “PetroStroy” is external and internal mechanized wall plastering. Elements of brick buildings are quite common. Their finish is characterized by some features.
Thanks to the plaster finish, visible defects in the brickwork are completely corrected. In addition, the strength of the wall is significantly increased, the indicators of noise and heat insulation are improved. Most often, a rough finish is made, in some cases a fine finish with decorative plaster is also used.
For leveling brick walls of houses and apartments with plaster, cement-sand or gypsum-based mortars are used, depending on the requirements for resistance to dampness and temperature changes. Cement compositions are considered universal, they are used for outdoor and indoor work.
Inside heated premises, brick walls are most often plastered with gypsum plaster. It is more plastic, lighter, it is much easier for craftsmen to work with it. Gypsum-based mortars are well leveled. It turns out a smooth surface, completely ready for painting, wallpapering.
Brick walls are ideal for machine plastering. The developed surface contributes well to the strong adhesion of the plaster layer to the base. In addition, the plaster mortar is characterized by increased adhesion to the material for the manufacture of all types of bricks.
This is due to the porous structure. During the laying process, masons do not specifically remove small influxes of mortar at the seams and do not close up minor depressions. This speeds up the process of bricklaying, contributes to an additional increase in the adhesion strength of the plaster to the wall.
If there are noticeable deviations in the plane of the masonry, it will be necessary to eliminate the irregularities with a large layer of mortar. In this case, brick walls are plastered according to beacons . As such landmarks (marks), most often, profiles made of plastic or metal are used.
Installation of lighthouses is carried out after preparatory work, including cleaning the surface from contamination, treatment with a primer. Machine application of plaster mortar according to the marking is faster and more accurate. The process of leveling and smoothing the plaster is also accelerated.
Exterior Brick Wall Plastering Compounds
For machine finishing exterior brick wall plaster , only sand-cement based mortar is used. It is prepared immediately before use from a special factory-made dry mix for mechanized plastering.
The composition of the building mix includes sand of medium-coarse fraction, high-quality cement, modifying additives that increase the plasticity and lifetime of the solution, reinforcing polymer fibers that increase strength and reduce shrinkage of the plaster layer during setting (drying).
Facades of buildings and other external brick walls are finished with this plaster mortar. It is also used for rough finishing work in rooms, if there are increased requirements for the strength of the plaster, resistance to moisture, and temperature changes.
For finishing brick wall plastering, the price depends on the type of mortar used, on the area of the surface to be finished, its condition and complexity (evenness, the presence of openings, interfaces, junctions), the speed of order fulfillment.
Cement-sand plaster mortar forms a kind of monolith with a brick wall. Such plaster is characterized by high strength, hardness, maintainability, a long period of operation, numbering tens of years.
Plastering works from “PetroStroy”
Take advantage of the offer of the construction and repair company PETROSTROY, if you need to make a rough finish of external or internal brick walls. The masters of the company have experience in mechanized plastering of more than 500 objects in Moscow, the Moscow region.
German-made PFT RITMO XL plastering stations are used in the process of finishing work. Dry building mixes supplied directly from the manufacturer are used (savings up to 30%). We have our own transport for the delivery of building materials and equipment to the site.
All-purpose plasterers of the company have mastered all types of machine rough finishing of walls of rooms, facades of buildings, semi-dry floor screed, finishing decorative plaster. The customer is guaranteed even, smooth walls with right angles, attractive competitive prices.
How to plaster brick walls
Home Leveling and plastering walls and ceilings How to plaster brick walls
Brick walls are often far from ideal: uneven, with a protruding or littered part. Therefore, a quality repair must begin with the alignment of the walls. For this, it is necessary to plaster those same brick walls.
In addition, plaster is the cheapest and most common finishing method. In addition to leveling brickwork, it enhances the protection of the wall from moisture, increases the effect of sound and heat insulation of structures. With the help of plaster, various decorative effects are created.
The retention of the plaster coating directly by the wall surface depends on the preparation of the surface for plastering the brick wall, which is the cleaning of the wall from grease and oil stains, efflorescence, protruding reinforcement, from mortar sagging. All this is cut down with spatulas or a hammer and a chisel. Then they clean the surface of dust (with rags) and install beacons. Every time, starting the application of a subsequent layer of primer or plaster, dust is removed. On brick walls that have a smooth surface with gaps between bricks filled with mortar, deep scratches are applied at the beginning of work or a notch is made with a special tool.
Monolithic or continuous plastering of brick walls is carried out in several layers. The plaster used is cement and can be of different quality, so simple, improved and high quality plaster stands out. Simple or continuous – spray and primer are applied alternately. With improved plaster – in addition to the first two layers, it includes a coating. When performing high-quality plaster, one more is added. Each stage of plastering has its own role.
Spray – the starting layer of plaster, thrown onto the prepared surface and filling all its pores. It provides the adhesion strength of the brick to the plaster layer. The solution for spraying is used in a creamy consistency. The thickness of the sprayed brick surface is 3-5mm. Before spraying, the brick is moistened with water.
Primer – applied as a second (basic) layer, forming the thickness of the entire plaster. If it is necessary to significantly increase the thickness of the plaster, the primer can be applied several times.
Coating is the final or final layer of plaster (smoothing). It is applied in a thin layer, it is well leveled and rubbed. The next layer is applied to the previous layer after it dries. The plaster can be applied to the wall by brushing or spreading
The plaster is applied from the top of the wall downwards and starts by rubbing the inside corners. It is best to plaster in late spring or early autumn when the weather is warm. In the intense summer heat, plaster dries faster than it should according to technology. Therefore, cracks may appear on its surface.
For interior and exterior walls, ordinary plaster for brick walls and decorative plaster for facade and basement finishing of buildings can be used.