Author: Palace
Video: SuperGrip Challenge
Video: Tiling On Heated Floors
Video: Wet Room
Selection of Appropriate Paint Strippers
STRIP AWAY
REMOVES COATS OF
- Old Alkyd undercoat & Gloss paints
- Pre 1970s Lead based coatings
- Alkyd Varnishes
- Interior Artex paints (vinyl based)
- Vinyl Matt & Silk Emulsions
- Some “sprayed” exterior coatings.
SAFE ON SURFACES OF
- Softwood frames & doors
- Plaster / Brick / Concrete
- Glazed Ceramic Tiles, Glass & uPVC
- Cast Iron & Steel
- Stone & Slate
WILL NOT REMOVE
- Acrylic paints & stabilising sol’ns
- Polyurethane varnishes
- Two-pack epoxy paints
- Lime-wash / Snowcem
- Heat applied enamels & coatings
- Exterior paints with “Pliolite” resin
- Powder / automotive coatings
AVOID STRUCTURES MADE OF
- Hardwood timbers
- Veneers, Laminates &, Compressed board
- Resin – based plasters
- Aluminium & its alloys
- Gesso plaster
- Marble
STRIP AWAY LV
REMOVES COATS OF
- Water-based Acrylics
- Cellulose / Chlorinated rubber
- Polyurethane varnish & sealer
- Most exterior acrylic masonry paints
- French polish & Shellacs
- Pliolite based exterior paints
SAFE ON SURFACES OF
- All metals incl. brass, bronze & copper
- Aluminium and its alloys
- Hardwood timbers, oak & ash
- Fibreglass & uPVC
- Plaster / Brick / Stone / Concrete
- Softwood timbers
WILL NOT REMOVE
- Two-pack epoxy paints
- Powder / automotive coatings
- Heat applied coatings & enamels
- Lime-wash / Snowcem
- Old stabilizing solutions
AVOID STRUCTURES MADE OF
- Gesso plaster
- Veneers & Laminates *
- compressed board *
* Note: STRIP AWAY LV may be used on these surfaces providing dwell time is controlled and limited (test first)
Treatment & Prevention of Damp & Dry Rot
Rot is one of the major causes of timber decay in properties and will usually found be found where dampness from any source has been allowed to become established for a period of time. This creates the ideal conditions for wood rot spores to germinate and spread as a fungal infestation which progressively destroys the structural integrity of all types of timber.
DIAGNOSIS
The correct identification of dry rot is important owing to the extensive and elaborate measures necessary to control and eradicate it. The recognition of the various diagnostic features of the timber, mycelium, the strands and fruiting body is important for a positive identification appraisal.
A) TIMBER
Timber is a cellular material comprising mainly of cellulose and lignin, which provides the timber with rigidity and strength. Dry rot breaks down the cellulose of the timber, leaving behind the lignin, which gives the timber a darker colour. This darkening is characteristic of brown rot. As the wood breaks down, it loses strength and weight which causes cracking and shrinkage to occur. The wood may also appear warped. The decayed timber splits into cuboidal pieces with deep cracks along and across the grain caused by the shrinkage.
B) MYCELIUM
Fungal growth is dependent on the development of the hyphae: Fine filaments which elongate and spread through and across the damp timber. As the hyphae grow, they form a larger mass. The mycelium, which can appear as a white, fluffy, cotton wool-like growth or silvery grey sheets. The mycelium can also be tinged with lemon-yellow and lilac patches. The skin or sheet will peel back like a mushroom cap in straight lines. A musty mushroom-like smell may be present especially when conditions promote activity.
C) STRANDS
White or grey strands, which conduct nutrients and water, are formed within the mycelium. These strands, which can be up to 8 mm thick, will allow the fungus to spread over and through inert materials and reach further timbers. This ability must be considered when inspecting a dry rot outbreak. The strands will become brittle on drying and will “snap” audibly. This brittleness will distinguish the strands from other similarly coloured wet rot stands.
D) THE FRUITING BODY (SPOROPHORE)
The fruiting body can be the first indication of dry rot, although its development usually follows advanced growth. Shaped like a fleshy pancake or bracket, the fruiting body has a centre section covered with wide pores or folds, orange or reddish-brown coloured from which spores are produced. These rusty red spores are released into the surrounding area and disperse on air currents as red dust settling on horizontal surfaces.
APPRAISAL
Where dry rot is present the inspection must be carried out carefully and methodically. Remove affected skirting boards and floorboards and examine the sub-floor area, checking for fungal growths and testing the joists by prodding with a screwdriver or similar implement to determine the depth and extent of the decay. Assess the sub-floor ventilation, checking for a musty mushroom-like smell which may indicate activity and debris, which may promote the spread of the fungus or the germination of the spores. Check the plasterwork adjacent to areas of decay by removing small pockets to determine the spread of strands behind the plaster. If necessary, remove random bricks to examine the cavity for any signs of the fungus.
Determine the cause and source of dampness and rectify to promote drying conditions, paying particular attention to rainwater, goods, bad pointing, flashings and bridged damp-proof courses. Where dry rot comes into contact with a party property, the owners or occupier must be notified and if possible an inspection carried out.
CONTROL
The principal aim in the control of dry rot is to identify and eliminate the source of moisture and dry the building as quickly as possible to reduce the moisture content in the timber to below 20%. This procedure may take a long time and although it forms the basis for eradicating the fungal infestation, secondary measures may be required to prevent further damage.
TREATMENT PROCEDURES
Cut out and remove all decayed timber up to 600mm beyond the visible limits of the fungal decay depending on site conditions and severity of the fungal growth. Remove all built-in timbers, e.g. wall plates, lintels, bonding timbers within the affected area and replace using steel or concrete.
Remove all timber debris from the sub-site area and any surface fungal growth, which may be present on exposed areas of masonry.
Rake out mortar joints in areas where masonry sterilisation is required and carry out a thorough surface treatment using a coarse spray of PALACE fungicidal irrigation fluid, applying two or three treatments. This treatment is essential to ensure all residual spores from the infected timber are eliminated to isolate an existing outbreak and prevent any future recurrence of dry rot by constructing a cordon sanitaire using a method of drilling and injecting irrigation fluid into masonry or brickwork to form a sterile barrier located as follows:
- Between an outbreak and timber in the immediate area which is not affected
- At the base of a wall with no DPC membrane established in infected wood beneath a solid floor
- To brickwork where fungal decay by dry rot has affected timbers or masonry in a party wall with adjacent property
- To isolate and protect built-in timbers which may be affected by are not readily removable.
Re-plastering of exposed brickwork should be carried out using PALACE Fungicidal Waterproofer. This is especially important in areas where a severe infection is evident or in a party wall situation where access is not available to both sides of the wall.
The replacement timbers should be pressure-impregnated and cut-ends retreated using PALACE Universal Wood Preservative timbers PALACE Timber-Treat Ecology. The ends should stand in the preservative for a minimum period of one hour to ensure penetration up the end grain. Residual sound timber in the area of the outbreak should be cleaned and treated using PALACE Universal Wood Preservative
To prevent any future recurrence of a fungal outbreak it is important that the property is well maintained to prevent any ingress of damp. Also, be sure all external protective measures are kept in good order
Guide: Tiling On Floating Floors
DESIGN CONSIDERATIONS
All tile fixing should be carried out in accordance with BS 5385: WALL & FLOOR TILING Part 3 1989 – Code of practice for the design & installation of ceramic floor tiles and mosaics. Section 14.4 of this standard emphasises the need for timber substrates to be more than suitable for carrying the expected load and they be stiffened prior to tiling. Ceramic floor tiling should never be installed on floating timber floors subject to heavy static or dynamic loads.
This latter point emphasises the fact that a timber base alone may allow deflection, which is beyond the tolerance of the ceramic covering to be applied, therefore the need for rigid sheeting and screw-fixing is essential to ensure stability and rigidity.
Floating floors, by definition, are not fixed to the base substrate and so, before tiling a floating floor, it is essential to determine that its structural stability is sufficient to meet the requirements of BS 5385, part 3, section 14.4.
A typical floating floor lies on a concrete base and is characterised by a layer of rigid insulation topped with flooring grade plywood or chipboard (18 – 20mm deep). The insulation layer should be of sufficient density to provide firm support to the overlaid board. Expanded polystyrene is not considered to be a suitable underlayment for a floating floor which is to receive ceramic. To further ensure the rigidity of this structure, the timber board can also be constructed as a raft fixed onto timber battens (45mm x 45mm) with the insulating material laid between them.
SUBSTRATE STRUCTURE
To prevent excessive deflection, it is essential that the board is 18mm – 20mm thick and that the insulating material is sufficiently dense and rigid to support the expected load without risk of excessive compression or movement.
Joints between the sections of chipboard should be tongue-and-groove located and bonded with a waterproof wood adhesive. Any dead joints between adjacent boards must be fully supported as butt-jointed edges to prevent deflection between the two.
All timbers used in the construction of the floor must be moisture-stabilised to the conditions expected within the finished location. Expected moisture-stability should be further protected by the installation of an effective damp-proof membrane within the base structure and provide sufficient heat and ventilation to control humidity within the service environment.
Timber surfaces receiving tiles should be clean, dust-free and clear of any surface coatings likely to impede the adhesive from forming an effective bond to the surface. The use of Tiler’s Primer (SBR) is also advised on all worn or porous timbers and composite boards.
The base substrate must also be even, level, stable and with no localised depressions or elevations likely to cause uneven compression of the insulation layer.
Where the above precautions have failed to secure a stable surface, free from deflection and movement, it will be necessary to overlay the existing board with water-resistant plyboard to a minimum 18mm resistant thickness, laid with staggered joints. Also, battens to support the boards should be fixed to the base substrate at 300mm centres and then install the insulating layer and overlaying boards prior to tiling.
N.B. Do not proceed to fix the tiles if, after all preparatory measures have been taken, the floating floor still shows signs of deflection or movement likely to exceed the rigidity required by the ceramic tiles when subject to the anticipated loading.
TILE FIXING
Use PALACE Super-Flex two-part adhesive laid using a floor-grade notched trowel to achieve a solid adhesive bed of not more than 6mm thickness.
GROUTING
Use PALACE Flexi-Grout for joints from 3mm up to 20mm wide. In grout situations where heavy trafficking is likely to result in more movement, Flexi-Grout mixed with Palaflex additive (pre-diluted 1:1 grout (pre with water)) will provide even greater movement tolerance.
N.B. All polymer-modified grouts should be cleaned from tile surfaces within 1 hour of being applied as they can be extremely difficult to remove when set.
MOVEMENT JOINTS
It is essential to ensure that the full perimeter of all floating floors is sealed with a silicone sealant-based movement joint to a minimum of least 6mm width (in accordance with BS 5385: Part 3 – 1989, clause 19 to 23). This requires joints at all perimeters of the tiled area, coincidental with existing structural movement joints in the substrate and across large floor areas at 8 to 10m intervals.
Guide: How to Grout & Avoid Colour Variations
INTRODUCTION
It should be noted that due to the variety of application & environmental issues likely to influence the curing of a cement-based grout joint, that it is virtually impossible for the dry composition of the pre pre-blended grout powder to produce localised variations or patchiness in the appearance of the applied grout without first having been affected by any one of the patchiness following factors, all of which are beyond the control of the manufacturer.
MIX CONSISTENCY
It is essential to ensure the powder is mixed thoroughly and consistently in a clean vessel with clean water to form a smooth, homogenous and lump-free paste. Additional mixes of grout for larger projects must be produced from the same batch of powder, using an identical water addition, whilst again achieving a fully consistent, smooth lump-free paste. Never excessively add more water than the recommended volume
JOINT PREPARATION
All joints to be grouted must be of consistent depth and raked clean of any adhesive residue as any contaminant in the open joints will consequently result in irregularities in the depth & consistency of the freshly applied grout. Both of which may result in shade variation.
TILED SURFACE CLEANING & JOINT FINISHING
Immediately after grouting when wiping down to remove the excess mortar from the tile face around the joints, care must be taken not to ‘over-wet’ the freshly compacted joints, as this may affect water content in some joints but not in others, leading to a higher concentration of fine surface laitance and would raise the possibility of a lighter shaded surface appearance in these areas.
Brushing or dry-wiping over a grouted floor joint when the paste has bodied up, but is still not set can disturb the surface finish and open up the texture of the grout to give a coarser and darker shade than when the grout was first laid and finished off with a wet cloth or sponge and any contact with the surface at this point in time must be even and consistent over all areas to ensure the hardened appearance retains an equivalent degree of dryness and surface texture, otherwise shade variations are likely.
GENERAL SURFACE MAINTENANCE
When cleaning the completed tiled surface, you must ensure that the materials and cleaning agents used are applied consistently, are not used at excessive concentrations and are rinsed off promptly as soap and detergent residues can accumulate in joints and affect appearance, particularly when exposed to moisture.
EFFLORESCENCE
The initial set & hardening of a cement-based grout may result in surface salt & lime deposits forming as water evaporates, known as ‘lime bloom’ and happens when excess water is present either in the mix or after washing the grouted surface.
Efflorescence can also be become apparent when water penetration occurs either through the surface of the cement-based material or from sub-floors where no effective and adequate damp proof course is in place. This phenomenon often diminishes over time with repeated surface washing & drying, however control of mixing water dose and also the wash cycles during the removal of grout stain residues will also reduce risk of efflorescence in the cured joints.
SUBSTRATE TYPE
Variations in the density or porosity of the surface beneath the tiles will encourage some areas of the grout joints to dry out at a different rate to others, usually illustrated where darker areas of the grout are laid over dense or impermeable section of flooring, whereas lighter shades will be evident over the more porous and drier sections of the substrate flooring.
SERVICE CONDITIONS
The end use of the tiled location needs some consideration as this may result in some areas being exposed to wetting more frequently than others, which consequently will result in the damper sections appearing slightly darker than the drier areas. Regular and localised wetting of one area at a more frequent rate than the surrounding tiled area will result in a shade variation due to the moisture level retained within the cured tile joint.
TILE TYPE & FINISH
Porous tiles, substrates or joints adjoining the cut edge of a tile will be exposed to greater risk of moisture absorption from the wet paste than less porous surfaces or true tile edges. This can produce localised variations in moisture content and when fully cured will manifest in a shade variation from joint to joint.
SUMMARY
To maintain an ideal consistent appearance in all grout joints, it is essential to ensure consistency is applied at all stages of the application process, including the type of tooling used to finish off joints, the amount of moisture introduced & allowed to remain when cleaning the tiled surface and the finish time which elapses between initially compacting the joints and then returning to tool the joints to a smooth clean edged finish. Where any one of the above precautions is not followed then it is possible to encourage shade variation in the final colour of the hardened grout, which may only then resolved with the application of a mildly acidic surface cleaning agent.
It should be noted that in most cases, the lightening of dark joints is due to efflorescence blooms of naturally occurring lime which is released by drying cycles from within the Portland cement base. This is often a transient feature as the natural cycles of wet & dry periods following cleaning or exposure to weather (if external) will result in the surface stabilising to a consistent shade as the lime is washed away.
A document is also available here for printed reference.
Guide: Tiling On Timber Floors
DESIGN CONSIDERATIONS
All tile fixing should be carried out in accordance with BS 5385: WALL &FLOOR TILING Part 3 1989 – Code of practice for the design & nstallation of ceramic floor tiles and mosaics and the Tile Association guide – “TILING TO TIMBER SHEETS BOARDS & TIMBER SUBSTRATES. Section 14.4 of BS 5385 part 3 1989 emphasises the need for timber substrates to be more than suitable for carrying the expected load and then be stiffened prior to tiling. The moisture content of timber can vary depending on the temper temperature and humidity conditions depending on it’s storage location. To ensure dimensional stability of structural timber it is essential to allow time for the moisture content of the wood to form an equilibrium with the ambient conditions of the environment where it is to be permanently installed. Composite wood boards will stabilise to lower moisture contents than is the case for solid wood structures. Timber should be conditioned to suit its’ intended environment by storage for a suitable period of time until the moisture content stabilises to an acceptable level. The table below indicates the normal “in “in-service” moisture contents for softwood timbers, studwork & battens:| Conditions | % moisture in Softwood timbers | % moisture is composite boards |
| Unheated | 15 – 19% | Up to 15% |
| Periodic heating | 10 – 14% | 9 – 12% |
| Continuous heating | 9 – 11% | 7 – 9% |
| Under-floor heating | 6 – 8% | 5 – 7% |