- Practical advice
- Make room clear
- Good seating
- Every stone in its place
- Take his time
- Treat the angle recovery
- Seals: it's up to you!
- Healthy foundations
- Wall mounting
- The angle recovery
Over the years, the party wall has deteriorated sharply. Two cooperative neighbors, free time and everything is refurbished for a very reasonable cost.
Cost: 450 € for this project
Time: 1 good week to two
Equipment: crowbar or crowbar, pickaxe, meter, spirit level, cord, wheelbarrow, shovel, rake, concrete mixer, 10 liter bucket, grinder with metal disc, hammer, trowel, trowel, cat tongue.
Lime remains irreplaceable
Stone masonry needs to "breathe" to remove moisture. An essential principle when it comes to taking an old masonry, as our corner chaining. There is no question of forming a watertight barrier by using a cement mortar. The remains of the masonry period, linked with the earth, would risk experiencing disorder again. The qualities of lime are irreplaceable and it is she who serves as a binder mortar.
Here, the mixture consists of 30 liters of sand for 10 liters of natural hydraulic lime, supplemented with 1 liter of cement. For the water, the dosage is generally carried out by successive addition, in order to obtain a relatively compact mixture, unctuous but not liquid.
When a crack opens inexorably and leads as here the gradual detachment of part of the wall of the house, it is best to purge all elements that may collapse to rebuild afterwards. This is the solution that has been chosen for this project. In the wake, the owners have decided to cut down a portion of the wall in bad condition and rebuild it.
Make room clear
With this type of masonry, especially built with clay soil, disassembly is no problem. A crowbar or a crowbar is enough to take off the rubble. Remember to spread your piles of stones on both sides of the wall to limit handling during reassembly. Side wall, everything is removed on 5 m long to start from the ground. On the other hand, the corner chaining of the wall bordering the awning is just purged (open) on the whole dubious zone.
The foundation of the new wall consists of a running foot reinforced by embedded steels and a welded mesh. With such a seat (30 cm high), the wall is not likely to work on its base!
The concrete of the foundation is a fairly fluid mixture made with 40 liters of gravel (calibration 20 to 30 mm), 30 liters of sand, 1 bag of cement 25 kg and 15 liters of water. A concrete mixer (which can be rented for the occasion) avoids the manual brewing fatigue and makes it possible to obtain a homogeneous mixture every time.
Every stone in its place
In principle, mounting a stone wall poses no problem. The elevation is carried out rank by row and the system is identical each time: we tend a rope on each side of the future elevation to materialize the edges, then the stones take place one by one on a bed of mortar.
Everything is then a matter of glance in the placement of the stones to obtain a rank of a thickness roughly constant, with beautiful faces of facing. The central part of the wall is made with stones of small disparate sizes. They mainly serve as filling to reduce the consumption of mortar.
A new mortar layer is then used to fill the interstices and serves as a seat for the next row. From one row to another, the stones must be offset joints, as for all masonry.
Take his time
This type of achievement is a matter of patience. Each stone is put in place and a few small hammer strokes allow better adhesion with the mortar. This wall is built in strips of about 50 cm high. Indeed the fluidity of the mortar requires waiting until the beginning of the catch, otherwise the whole is deformed under its own weight. In case of rather heavy rubble, it is better to be limited to two or three rows.
As soon as the mortar begins to take hold, return to the previous ranks and lightly scrape joints on the front. Just clear enough between the stones to reserve space for future finishing joints.
Treat the angle recovery
Purgée of all the rubble disorganized or non-adherent, the recovery of the angle presents no particular difficulty. This part is rebuilt as and when the elevation. A watering of the masonry in place improves the adhesion of the recovery. Here too, the work progresses rank by row, following as much as possible the wiring lines of the existing wall.
To finish the crowning (or chaperone) that caps the top of the wall is achieved with tiles recovery channel. A finish that harmonizes with the existing and rejects water away from the wall.
Seals: it's up to you!
If the joints participate in the elegance of the wall, their dosage remains a big topic of discussion between amateurs. Everyone agrees to favor lime. But some people advocate the use of a mixture based on hydraulic lime, which has the property to make part of its catch in the water and the other in the air... While others swear by one mixture of natural hydraulic lime (NHL) with slaked air lime.
The mixture has the property of making its setting in air only by reaction with carbon dioxide, its final setting is much longer.
Hence two recipes...
1) a bag of 35 kg of XHN + 90 l of sand + 20 l of water.
2) 20 l of NHL + 20 l of CAEB + 100 l of sand + 30 l of water.
When dismantling, spread the heaps of stones on each side of the wall and make a withdrawal to maintain free movement during the work. The corner chaining is just "purged".
Along the 5 m of dismantled wall, the ground is simply scraped to form the foundation. Pour the first layer of concrete, then place the irons and cover with another thickness.
Rake to form a constant thickness over the irons. It is better to be two for this work (one to the concrete mixer, the other to the foundation).
Arrange a welded mesh on top of the second layer when it is still liquid. Pour a final layer of concrete and level the surface that will serve as a seat.
Let your foundation harden for 2 or 3 days. Stretch the strings materializing the limit of the stones of the first rank, prepare your mortar of lime. Spread a layer of 3 or 4 cm.
Choose stones of approximately equal thickness and wedge them one by one along the string. Improve grip with a few hammer strokes. Work on both sides of the wall.
Fill the interstices with smaller rubble. This is an opportunity to break the stones without interest to fill the voids. The more stones there are, the less the mortar will be consumed.
Pour mortar in the center of the wall so that the mixture creeps between the stones and forms a homogeneous whole. Help to penetrate by tapping the tip of the tip of the trowel.
When everything is well filled, bring the excess mortar back to the edges of the wall and cover the top of the stones. This layer will serve as a seat for the next row.
Start placing the next row according to the same principle. Make sure to arrange your stones on the previous horses. The ideal is to get an offset joint every time.
When the mortar of the first rows begins to take, scrape along the joints to reserve the space of the future jointing with "stone view". Scrape on 1 to 2 cm.
Do not hesitate to vary the thickness of the rows to give a certain "rhythm" to your equipment. Reserve the beautiful corner stones for a possible chaining.
The angle recovery
The chaining zone is watered to facilitate hanging. Do not fear the presence of earth. As long as an old wall is jointed on each side, the whole can face time.
The resumption of chaining takes place on the same principle, masonry rank by rank. Constitute each time a kind of bearing almost flat and fill the smallest hollow.
The boundary between the party wall and the corner chain is lined with corner stones. This preserves the "visual" separation between the two wall bodies.