TIPS
Surface Preparation
One of the main elements for the waterproofing success is the construction quality and the structure or substrate preparation to receive the waterproofing material.
The waterproof system shall have adequate characteristics, so that it can bear the requirements. However, many times we have observed constructive mistakes that damage or harm its good performance such as:
- Inadequate armatures coating.
- Drains, pipes, etc. wrongly fitted.
- Concrete placement gaskets badly performed.
- Segregated concrete with nests, grubs, etc.
- Regularization of the slab performed with inadequate trace, without curing, under dirty substrate, detached, with fissures, etc.
- Use of inadequate materials for the construction of flower boxes, etc. (bored bricks).
- Performing the fillings with debris, before performing the waterproofing.
- Not respecting the distinct thermal expansion among the several construction materials.
- Presence of contaminant elements such as oil, grease, demoldant and cure agents inadequate to the waterproofing system.
Some of the necessary preparation cares of the several types of substrates are related below, grouped as:
Surfaces in concrete which will receive direct waterproofing, such as: Curtains, Reservoirs, Subsoil, Etc.
General conditions to start the service
- Unformed concrete and cured for at least 28 days with a minimum of 3,0 cm armature coating.
- Remainder of wood, iron tips, disaggregate concrete or any other elements that do not belong to the removed structure.
- Drilling, drains, passing tubes of the performed and approved installations.
- EPost rest, railings, and other elements fixed on the structure, accomplished and approved.
- Solders for dock ladders, guides, lightning rods, etc, rigidly fixed.
- Unobstructed, clean area cleared for the beginning of the work.
Executive Methodology
- To detect all concrete placement failures, nests, etc. removing the loose aggregated material up to obtaining a firm and homogeneous concrete.
- During the concrete removal, you must try to achieve a concave cavity, with a sloping superior border, in a way to make the repair adherence easier.
- Mold mooring iron tips shall be cut at a minimum depth of 3 cm into the concrete interior.
- If there is a mold locking system, through bolts or recovered locks, remove the PVC tube and ream the smooth surface left by the tube, using an electric drill, with a diameter equal to the hole.
- The recomposition of the concrete placement failure and the holes filling and necessary repair shall not be performed with common mortar. For thickness up to 7 cm they shall be preferably performed with industrialized modified mortar with acrylic polymers Denvertec 700 (30 mm to 70 mm thickness) or with cement and sand mortar in trace 1:3; kneaded with water and acrylic adhesive emulsion, Denverfix Acrílico in trace (2:1) according to the following:
- Perform the substrate cleaning through washing with clean water. Damp the substrate and brush the contact surface, with kneaded cement paste with water solution and acrylic adhesive emulsion, Denverfix Acrílico trace (1: 1) and immediately after performing the repair.
- For repairs of more than 7 cm thick, perform the repair with Denvergrout in the shim consistency by the Dry Pack system, or perform the pipe type concrete placement.
- Follow the care procedures related to the repair cure:
Dry Pack:
- Clean the surface in contact with the repair with the help of a water jet, to remove the loose particles and dust.
- Damp the cavity up to the substrate saturation, eliminating occasional water puddles.
- Perform the repairs with Denvergrout in the plastic consistency (shim) using water factor /Denvergrout in weight 0,10 (2,5 l of water for each 25 kg bag) .
- Or to perform the same work with mortar, prepare a mixture of cement and average sand, in 1: 2 proportion, in mass.
- Add water little by little until you notice the mortar moistening.
It is important that this mortar is only humid, not having the conventional mortar consistency. Its performance will be controlled during the mixture homogenization, with the hands without them becoming wet.
- Pound the mortar in the cavity with the help of a wood socket, with a tip of approximately 3 x 3 cm, in layers of not more than 1 cm thick, up to the complete filling of the cavity.
- Remove the excess, with a trowel and perform the finishing with a wood or felt mortar board.
- After the superficial hardening of the repair, perform the cure with water, for at least 7 days.
a) "Pipe” type concrete placement:
- Remove, manually or mechanically, all the segregated concrete, until the concrete is firm and homogeneous.
- During the segregated concrete removal, you have to try to obtain straight fronts to make the confection and mold mooring easier.
- The corners shall be round, the borders at right angles and the superior faces of the region to be repaired, shall be inclined, in a 1:3 proportion in relation to the repair thickness.
- In case of failure that crosses the whole part, put a fixed mold on one of the sides of the region to be repaired, with dimensions superior to the repair areas. If not, the homogeneous concrete itself will serve as a support for the repair.
- On the side used to perform the repair, put a fixed mold on the inferior part of the area to be repaired, leaving a void that allows the entrance of an immersion vibrator.
- An inclined mold with a “pipe” shape is placed on the upper part, with a height of approximately 10 cm, above the failure. This pipe aims at guaranteeing the contact and adherence on the superior face, in the old concrete and new concrete bonding.
- Clean the surface which is going to be treated, leaving it free from loose particles and dust.
- Saturate the concrete substrate, next eliminating occasional puddles.
- Perform the concrete or graute launching, Denvergrout.
- After around 18 hours of the concrete placement work, the “pipe” is removed and the projected concrete is cut.
- The molds may be removed after 24 hours after the concrete placement is over.
- The cure of the concrete or graute used in the repair shall be performed cautiously, you may choose curing with water for at least 7 days, or using a curing product which does not interfere in the adherence of the waterproofing work to be performed.
- Clean the surface before beginning the waterproofing work.
Mortar and concrete surfaces to be regularized, such as: Slabs in general, footboards, mortar, etc.
General conditions to start the services
- Conclude mortar.
- Piping of the installations rigidly fixed.
- Structural repairs performed according to item 1.
- Post rest, railings and other elements fixed on the structure, performed.
- Anchor bolts for aerials, lightning rods, holding hoods for maintenance rocker arm, etc. rigidly fixed. Ready trapdoor bases, domus, etc.
- Clear, clean area, closed for the work.
Executive methodology
Horizontal regularization mortar performance
- Levels Points:
- Mark the water outflow levels quotas, drains locations, structural gaskets and all the necessary points to prepare the outflow diagram, observing the fall of at least 1% or according to the specified in project.
Obs: Swimming pools and reservoirs do not need falls.
- Strips of wood:
- After preparing the water outflow diagram, make mortar strips of wood, with the objective of having a template of the work.
- Mortar:
- Work with maximum spacing of 2,0 m and regularization with cement mortar and sand trace 1:3 or 1 :4, with at least 2,0 cm thick.
- Cut into laths and straighten this mortar with the help of a wood mortar board, promoting a velvet finishing without burning it.
- Make the live corners and edges round every time the waterproofing system requires.
Vertical regularization mortar performance
- In mortar:
- Cut into laths and straighten the regularization mortar, with maximum thickness of 1,5 cm, promoting a straightened finishing.
- In concrete:
- Only perform corrections where necessary, following the procedures described in item 1. 2. 2.3 Slabs where the fall is not necessary: Ramps, tank bottom slabs and reservoirs.
- Perform these slabs with a lot of care, providing straightened finishing with wood mortar board.
- In case there are significant depressions or protrusions, above 5 mm, provide cutting of the protrusions and correcting the depressions, with cement mortar and sand, trace 1: 3, added with acrylic base adhesive DENVERFIX ACRÍLICO, in the minimum thickness of 2 cm.
Surface in soil, such as irrigations channels, lakes, etc.
General conditions to start the services
- The soil shall be compacted accordingly and able to keep its stability when it is submitted to incident loads.
- Passing points of piping, siphons, bases for overflow meters, etc. shall be placed according to the project details.
- All transition points between the soil (flexible substrate) and other rigid substrates, shall obey the specific adequate details for each case.
- The side and intermediate anchoring trenches shall be excavated in the project dimensions.
Executive Methodology
- Remove all pointed and bruising elements that may damage the waterproofing, such as stones, plant roots, etc.
- If there is any irregularity in the soil that cannot be eliminated, provide its regularization, using a layer of cement soil made with the local soil or provide a mount layer with fine sand.
Cleaning
The surface that will receive the waterproofing work shall be clean and free from dust, loose elements, oil, grease, demoldant or any impregnating element that may damage the adherence to the system.
The surface humidity degree shall obey the needs of the type of waterproofing to be used.
Exception is made to the application of blankets directly on the soil, because it is a system where there is only glue on the seams and the anchorage is performed mechanically.