The most common complaint made of old steel windows is the operation of the opening windows and the force that is required to close them. This also in turn leads to the ironmongery (mainly handles and hinges) being damaged by the force they are under. This problem can be relatively easily rectified by our skilled site operatives.
The problem exists because before the modern day method of factory polyester powder coating steel windows was introduced - all steel windows were painted on site. Subsequent redecorations usually then consist of a light rub down followed by additional coats of paint. The build up of paint around the hinge and pivot areas then leads to distortion of the frames where the opening windows have been forced closed.
We offer a service, to Service, Ease and Adjust these problem opening windows which comprises a very skilled method of easing, adjusting and lubricating the hinges and pivots / ironmongery and easing the frame members back to square. Only very distorted frame members will require the frames to be de-glazed prior to and re-glazed (with new glass) after the straightening works. The window frames will require redecoration (by others) after these works are completed due to damage that will be caused to localised paint areas. Should we take any externally exposed surfaces back to bare steel during this operation, we will coat the affected area with a zinc rich steel rust neutralizing / inhibiting primer paint to temporarily protect the surface from corrosion before decorators are employed to redecorate.
If broken or cracked glazing exists, we can:
(refer to glazing method that suits existing windows) :
Putty glazed panes :
Rake off old glazing putties, remove broken pane, clean out all old glazing mastics from the glazing rebates, treat any signs of rust within the glazing rebates and coat affected areas if necessary with a zinc rich rust inhibiting primer paint, supply new pane of glass to match original (if still available or nearest type if not), re-putty glaze with new glazing sprigs and non-setting metal casement putty. New glazing putties will require redecoration by others after re-glazing us carried out. Please allow at least 1-2 weeks after glass installation to allow the new putties to "skin" over before decorating. This will ensure the surface of the putty is not "scored" by the action of the bristles if it is not set sufficiently.
Metal beaded glazed panes (channel type clip-on beads) :
Remove and dispose of old metal bead and corner clips (if present), remove glazing studs from steel frame and dispose of, remove broken pane, clean out all old glazing mastics from the glazing rebates, treat any signs of rust within the glazing rebates and coat affected areas if necessary with a zinc rich rust inhibiting primer paint, re-drill and tap steel glazing rebates and supply/fix new glazing studs to new holes, supply new pane of glass to match original (if still available or nearest type if not), re-glaze pane using Butyl non-setting metal casement glazing compound with a colour sympathetic to frame colour, supply new metal beads to match existing (generally either 13mm wide x 13mm high, 9.5mm wide x 13mm high, 8mm wide x 13mm high, or 13mm wide x 9.5mm high, extruded aluminium sloping beads that do not require corner clips were also sometimes used), supply and fix corner clips to intersection of beads, alternatively - glaze pane using setting and spacer blocks and apply a silicone cap back and front to provide a longer life seal. Decoration of new metal beads is to be by others.
Metal or Hardwood beaded glazed panes (solid metal or hardwood beads secured by visible screws on face of beads) :
Remove and dispose of old metal or hardwood beads, remove broken pane, clean out all old glazing mastics from the glazing rebates, treat any signs of rust within the glazing rebates and coat affected areas if necessary with a zinc rich rust inhibiting primer paint, re-drill and tap steel glazing rebates ready for new bead screws, supply new pane of glass to match original (if still available or nearest type if not), re-glaze pane using Butyl non-setting metal casement glazing compound with a colour sympathetic to frame colour, supply new metal or hardwood beads to match existing, alternatively, glaze pane using setting and spacer blocks and apply a silicone cap back and front to provide a longer life seal. Decoration of metal or hardwood beads is to be by others.
See glazing safety note at foot regarding Health and Safety
During the long life of a steel window, the sealants used in sealing windows to their structural openings and the seals between window frame elements will eventually break down. Sealant technology in the 1930's was not as good as it is today and with modern chemicals - the sealants used today have a much longer life. Therefore, the seals may have to be re-made to existing windows. The method of carrying out this works is firstly remove and rake back all old sealants during servicing and overhaul works. Once the window frames have been redecorated - the seals can be re-introduced. This should be done after a sufficient amount of time has elapsed for the paint to dry. The external perimeters can be silicone sealed with a triangular fillet of (usually, dependant on structure and paint surface) low modulus gun-grade silicone sealant. Intermediate couplings which project from the outside of the window zone face can also be sealed in the same way. If the building is an active building site, it is often prudent to wait until all demolition works are completed as dust will adhere straight to silicone and it cannot be removed after. Under no circumstances should the silicone be painted after application as this will break the silicone seal down.
As opposed to re-glazing an entire pane (see section 5) - there may be a requirement to just replace individual glazing beads. This may be because of abuse, or because of (in the case of hardwood) - natural deterioration. Although it is possible to replace individual beads, because glazing rebates need to be re-drilled and tapped for either glazing bead studs or bead screws, this work is done without any responsibility for possible pane cracking during works. Therefore it is sometimes (especially if more than one bead per pane requires replacement) more economical to evaluate a job cost accounting for the entire pane to be replaced including it's four beads. Special profiled hardwood beads can be designed to match existing where part replacement is required. Metal clip on beads are still available. Refer to section 5 for details of bead replacement methods which are the same as if you were replacing a pane.
Steel windows before 1948 were not galvanised, although for a few years before this time - an initial coating of red oxide paint was applied to deter rusting of the members. Rust is not generally associated with windows after 1948 but whilst the galvanised technique was going through improvements in the first few years the coating was not as advanced as it is now and therefore not fully effective.
Therefore, windows from the early 1950's should not be showing signs of corrosion except for (a) localised area where galvanised coating was not applied correctly at manufacture, (b) windows have been damaged, (c) windows were not galvanised as they were manufactured by a company that stayed with the Red Oxide method of rust proofing.
Windows prior to this period are very susceptible to corrosion if site decoration is not kept up every seven or so years. This decoration should also include (if applicable) the replacement of glazing putties to stop water ingress to un-reachable areas under glass. Signs that this has not been carried out correctly is usually evident is rusting of the bottom sections and horizontal glazing bars.
99 % of commercial standard Universal Section steel profile bars used up to about 1965 are no longer available and because the front-to-back dimensions are different than used today in the equivalent W20 section, individual corroded bars cannot be cut out and new re-welded back in to replace them.
The SMW "F" series of steel domestic and light commercial sections is the same now as it was before, more or less, and therefore theoretically it is possible to cut out defective corroded bars and replace them with new bars. However, it has been found that is usually more expensive than replacing the window complete with a new replacement. Therefore, we do not carry out the replacement of individual bars and we strongly recommend the replacement of any window with major seated rust.
In the case of surface rust which is not seated in to the steel sections, this can usually be rectified by a competent decorator in the preparation of frames by rubbing down and treating with a zinc rich metal primer paint prior to normal redecorations.
If there is only local seated corrosion repairs, these can also be raked out to the best steel possible, treated with a zinc rich primer paint and filled with a suitable metal filler such as Isopon.
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Due to the problems with opening windows as described above and through, in addition to this, general wear and tear - ironmongery gets broken or missing throughout the life span of a steel window. This also includes the hinges and pivots.
A complete range of ironmongery, hinges and pivots are available to replace existing missing or defective items. This range includes new modern designs to suit the taste of the individual should all ironmongery be required to be changed for aesthetic reasons and also includes a range of period and original ironmongery where part replacement is required. We can offer ironmongery to match as closely, if not exactly to the original designs as possible to ensure continuity with existing ironmongery that is present and correct.
If the problem is with worn pins, rests or brackets that support ironmongery - these can be individually replaced. All replacement parts are drilled and tapped into the steel window sections to ensure a good fastening.
It should be noted that if the reason for the ironmongery to be missing or defective is that as described for problems 1 & 2 above - the windows should certainly be serviced, eased and adjusted prior to ironmongery works being carried out.
Should replacement hinges or pivots be required - this usually involves our operatives requiring external access to the windows concerned. All of our operatives carry on board their vans suitable access equipment to reach up to the 2nd floor level but above this level it is impossible to safely replace hinges / pivots without a scaffolding tower or full scaffold. The price of this is usually prohibitive for the sake of the occasional hinge and we suggest that we seal the window shut until, as in the case of blocks of flats, the next external redecoration is carried out.
It is often found in commercial buildings, where there are many floors involving larger than average opening windows such as the modular window designed buildings of the 1950's and '60s, that the window fixings and intermediate window coupling fixings have loosened off or sheared off. This is especially evident on the higher floors where windows have been more open to the weather and therefore the wind loadings applied to the face of the windows is much greater.
These fixings can be tightened or replaced as necessary relatively easily. The only problems that may occur is when fixing end is concealed under the glass edge (which is common on steel windows). This is only applicable to fixed light panes and not opening lights where the fixing screws are visible when the window is open. In this case - the fixed lights panes must be hacked out and re-glazed as described in the last section.
Many windows for about the last 30 years have had as an option a weatherstrip applied to the moving frame sections of an opening window which is concealed when the window is shut. This was, and still is, fixed to enhance the weathering capabilities of the windows and to stop draughts, water and noise penetration. This usually takes the form of (W20) a black neoprene rubber "fin" that is glued into a pre-formed grove in the inner moving frame section or (SMW) a black neoprene double bladed rubber gasket that is factory pre-fitted into an aluminium housing strip that is fixed to the inner frame by plastic fixings. The only other factory weatherstrip that was fitted was a large black neoprene gasket "fin" strip that occurs on SMW reversible horizontal pivot casements (that are used mainly on blocks of flats). This last type of weatherstrip is easily identified in that it is the only type that was fitted in factory by securing it between two separate steel outer frame members during construction.
If any of the above types of weatherstrips have been painted over on site it is likely that they have broken down. This is due to a chemical reaction between the paint and the rubber and always results in the rubber prematurely hardening, cracking and eventually falling off. In this case, there is no option but to replace them. This is possible with SMW windows and W20 windows but not the SMW Reversible Horizontal Pivot Windows.
The gaskets in the W20 windows can be cut out and replaced with new matching gaskets which are glued with a suitable adhesive to the original groove.
The gaskets and housing aluminium strip can be replaced to SMW windows. Note : this type of weatherstrip can only be replaced to existing SMW windows which presently have it fitted. Existing SMW windows without weatherstrips fitted cannot be fitted with it as special holes for the fixings have to be punched into the sections in the factory. Existing SMW windows presently not fitted with weatherstrips can be silicone draught proofed as described in Upgrading section.
The gaskets in SMW reversible horizontal pivot casements cannot be replaced as they are secured to the frames by two separate steel window sections which are all clamped together in the factory to ensure the tightness of the fastening. Again, should weatherstripping need to be re-introduced to this type of windows - they will have to be silicone draught proofed as described in Upgrading section.
Putty glazed panes: Putty glazed panes in steel windows are especially vulnerable to deterioration of the glazing system. This is more so when decorations have not been carried out every seven or so years. Externally puttied panes or internally puttied panes in bathrooms / kitchens (where there is a high level of humidity in the room causing condensation on the glass) are especially at risk. The visible signs of deterioration of glazing putties are cracks in the surface of the putty or a distinct gap between the putty and the glass. This problem should be rectified as soon as possible as the these cracks will let water in to the glazing systems where it remains trapped. The only path for it then to follow is in to the steel. In the case of original 1930's steel, before galvanizing was introduced in 1948, the steel is very open to corrosion through water penetration in the glazing system. This is evident by rusting of bottom members or horizontal glazing bars. If the problem has not been caught in time and the steel members are badly corroded - the window will require replacement - refer to replacement windows sections. However, if the steel is able to be refurbished, then the below methods will be employed to correct small areas of putty replacement. Please note that due to the nature of these works, we cannot be held responsible for breakage of glass. Although great care will be taken in the removal of putty, any panes broken will be advised and should replacement be required, we will carry out for an additional charge.
Rake off old glazing putties, clean out all old glazing mastics from the glazing rebate, treat any signs of rust within the glazing rebate and coat affected areas if necessary with a zinc rich rust inhibiting primer paint, re-putty glaze with new glazing sprigs and non-setting metal casement putty, New glazing putties will require redecoration by others after re-glazing is carried out. Please allow at least 1-2 weeks after glass installation to allow the new putties to "skin" over before decorating. This will ensure the surface of the putty is not "scored" by the action of the bristles if it is not set sufficiently.
Bead glazed panes : Bead glazed panes give a longer life to the steel window than putty glazed panes as above. Generally, bead glazed (either steel clip-on, solid steel or hardwood) panes were glazed using a Butyl type non-setting metal glazing compound in a solid bed or were glazed using setting/spacer blocks and capped back and front with silicone sealant. The latter gives a longer life. The only point that should be checked is the condition the of glazing mastic seal between the bead edge and the glass face. In the case of butyl glazing compounds, due to the life span being less than silicone, the compound may have hardened and cracked. This can easily rectified by scraping out the old mastics and replacing with new. The same method can be applied to silicone capped panes although this is a longer process. Silicone should never be painted over and if windows are site painted - decorators may have painted the silicone which would lead to premature breakdown of silicone seals.
See glazing safety note at foot regarding Health and Safety
Existing steel windows will be one of two finishes (if not left in a plain galvanised finish). The first will be site painted and the second, a factory applied polyester powder coating.
The latter finish is a very durable finish and should give no problems for a minimum of 15 years and we would expect no problems for at least 25 years. This is based on normal wear and tear. Polyester powder coating has been available for the last 15-20 years and so far we have encountered no problems with existing finishes. The polyester powder coating is applied directly to galvanised steel and therefore there should be no chance of rusting from inside under the coating. If damage is found to the powder coat finish or if a change of colour is required - it can be directly painted over with a normal gloss paint after normal decorating preparation (rubbing down to provide a key). We do not carry out site decoration works.
If the windows are site painted and there is not corrosion evident (see 'Section 9. Condition of frame members (rust)' if there is rust evident) there are two options for carrying out redecoration as stated below. We do not carry out site decoration works.
The first option would be to carry out a normal re-decoration. This would involve a rub down and preparation of frames (after Servicing, Easing and Adjusting and associated works by us as 'Section 1. Operation and distortion of Opening Windows')and top coating.
The second option is for the steel windows to be taken back to the bare steel front and back, the application of a suitable primer paint (we suggest a zinc rich primer for un-galvanised steel windows or a etch primer specifically for galvanised steel if galvanised frames), followed by undercoat and top coat(s). This would give the best result and would stop a mass build up off paint. It would also allow treatment of un-galvanised steel frames to add extra life span. |
