Stucco is traditionally a weather-resistant, attractive and durable finishing surface. It has been in use for a long time now with its advantages and possible downsides.
If you get the stucco work done perfectly following the manufacturer’s instructions, this cement-based house covering will last up to 100 years or more. But we often face a difficulty concerning stucco installation or repair, which is loose stucco, or stucco not sticking to wall or stucco falling off from the wall.
This problem is pretty common, but if certain measures are applied, the problem can easily be solved. The common solution includes, following the manufacturer’s directions, preparing the concrete surface or old stucco surface, applying a bonding agent etc.
How do I keep stucco from falling off?
If there is loose stucco on the wall and you are just trying to repair it, remove the loose stucco first. Then clean the bare wall, make the wall dust-free and structurally sound. Scrap with a stick, and make sure you have removed all the crumbling and loose material. You can even use a chisel and hammer and then brush and wash the surface to make sure a clean surface. Keep the surface a bit damp.
Then prepare the repair material. Add lime, cement and sand proportionately. If any less than the needed amount, the mixture won’t stick well to the surface. If you make the mixture too dry, it will also make the stucco fall off as it will not stick well. You can use hydrated lime, that will make sure the repair lasts years. However, to get utmost thickness, you can apply Portland cement and sand at 1:1 ratio.
Then you will need a bonding agent; a white glue, preferably Weldbond will just do fine. Apply the bonding agent mixing with water at a 10 to 1 ratio. Let the bonding agent dry on the wall, then apply the bonding agent again. At last, apply the coating.
Another trick is to apply a bonding layer of cement paint. You can make this paint by mixing clean cold water with Portland cement powder. Make sure the consistency is like regular paint. It helps to join new stucco with old stucco.
If you apply a bonding layer of cement paint, don’t let the paint dry and apply the stucco layer. If you need to apply two layers of stucco, wait at least 24 hours to let the first layer dry. Then apply the second layer.
What is the best surface to apply stucco to?
Stucco can be applied over any rigid or unbending material, which is attached to your support studs properly.
However, the most common surfaces that we apply stucco on are cement boards, plywood, oriented strand board (OSB), and, of course, the exterior grade gypsum sheathing. If you want to install sheathing material over any surface and then apply stucco, you must install the sheathing material by following local building codes.
Using a bonding agent
To make the stucco stick better, to patch over stucco cracks and holes, to apply stucco over painted concrete blocks, there is no alternative to bonding agents.
You might have heard about preparing the solid substrate efficiently so that you don’t have to use a bonding agent. Even wet stucco can be used over dry stucco to stick certain objects. But if you do this, the new layer of wet stucco will not be even with the rest of the stucco. So, it will require a whole new layer of stucco on the entire surface to even out the entire surface.
The bonding agents join the succeeding surfaces over the old surfaces and they both work as a unit because of the bonding agents.
Sticking to concrete
Being a combination of cement, sand, and lime, stucco is quite reliable as a finishing surface. It can be used on any exterior surface, and beautify those less outwardly engaging surfaces.
It can be applied to any concrete surface directly without the need for metal netting. Just make sure the concrete surface is properly cleaned and structurally steady to hold the stucco.But if you want to apply stucco over painted concrete blocks, you would have to get the paint off first and apply a bonding agent.
How do you stick stucco to concrete?
Whether you are applying stucco on Masonry or concrete, there is a common approach for applying stucco on both the surfaces. You just need to make sure that you are following the manufacturer’s directions and giving the layers proper time to cure well.
1. First, prepare the surface of the wall properly; clean the surface and make it structurally sound.
2. Then moisture the concrete surface.
3. Make sure a perfect mix of the scratch layer.
4. Now, apply the scratch layer and don’t forget to mark it.
5. Give the scratch layer a few hours, then apply the brown coat.
6. Then take a break and let the brown coat dry properly. Make sure to preserve the moisture of the brown layer during this period.
7. At last, apply the last layer, the stucco coat.
Does stucco stick to the wooden surface?
As mentioned earlier, stucco can be installed on any exterior surface to beautify such surfaces.
But to apply stucco on any wooden surface, you would need to use metal netting on the wooden surface, and then apply the stucco with a bonding agent.
How can I make stucco stick over a painted concrete block?
There is no way to make stucco stick over painted concrete block without getting the paint off first. So, you can either water blast or sandblast the paint in the first place. Then you would need a bonding agent. In this case, a water-based glue would do the job perfectly. It will stick the succeeding surface over the similar material’s old surface. So, you can use a PVA bonding. Put a coat of the PVA bonding over the old surface, then stick the stucco.
For the optimal result, go through the directions on the PVA bottle.
How can I make my stucco stick better on a cinder block wall?
The usual stucco formula is 1 part Portland cement to 3 parts sand. But, for block walls, to make the mixture/mud stick better, it is not an ideal formula. A somewhat richer blend will assist the mud with sticking much better compared to the usual blend.
To get a richer mix, the simple recipe is essentially adding somewhat more Portland cement. However, it is not like a 2 to 1 ratio; just adding a bit more of the Portland cement will suffice to make the blend stick better.
Lime would likewise assist with making the blend somewhat stickier and only a bit of touch of the lime will make the blend go far.
To conclude, although it is not a big deal to finish the stucco work, it can get complicated, as sometimes stucco may not stick to the wall properly. All you need to do is prepare the surface well, make the appropriate stucco mix and follow the manufacturer’s directions from the first to last.
You should utilize bonding agents to make sure the stucco lasts years.