DIY Replacement Windows, Doors, PVCu, upvc, PVC

Windows Today - information resource for Double Glazing Replacement Windows, uPVC / PVCU, Wood and Aluminium Save up to 65% off windows Click here to request a brochure
Windows Today Hoempage
Please choose a product
Windows Today Hoempage
Please select one of the options and Save up to 65% off the cost of new replacement windows
Double Glazing
Request Quotation for Double Glazing Windows Request Free Brochure for Double Glazing Windows Enquiries for Double Glazing Windows
Building Regulations
Types of Glass
Window Suppliers
Conservatory Suppliers
Garage Doors UK
Patio Awnings
Fascias, Soffits & Cladding
Plantation Shutters
Windows USA | Canada
More Information

Window Quotes Here


Ask an Expert - DIY

Please note: Most of the answers we feature here are from 1999 - early 2002. We endeavour to keep all links etc up to date, however if you spot any errors please let our webmaster know at It should also be noted that some replies may change in light of changes to legislation especially with regards to Planning Permission and Building Regulations. To submit a new question or to query an existing question visit

Question submitted by Brian

I am going to fit a PVCu door frame and window 1800x2100 approx. I assume I need to fix the top and bottom of the frame with frame fixers. I have read that drilling thro the bottom of the frame penetrates the water drainage channel. Is there a way of fixing securely and avoiding damp problems.

This question answered by Cavan Sullivan of Welsh Window Systems - - Many installers do not normally fix top and bottom of door unless they can not get addequate fixings through side. However if you do fix through bottom - seal hole with a good quality sealant. PVCu extrusions are multi chambered - you should make sure that you drill your hole and place the fixing through the chamber that is nearest to the inside of the property. (In practice this means that you should not "centre" the fixing on the frame)

Question submitted by Gerry

I would like to replace a sash window in my 1930's house with a upvc unit. Can I install the upvc unit into a sash box? And how would I go about doing this?

This question answered by Cavan Sullivan of Welsh Window Systems - You would remove the bead (sometimes called the parting bead) that the sash slides up against using a hammer and chisel and also cut the cord. You can now remove the sash. Repeat this process for the second sliding sash.

I would normally fit a rebated pvcu window rather than the normal equal leg section in this situation - although it is not essential. (Ask you manufacturer about "odd leg" or rebated PVCU outer frames - if this is not clear to you)

You will need to ensure than the outside timber is completely covered by thin pvc strips / cladding before installing the window. The bottom strip would be the widest. Ensure all strips are well sealed before fitting window against these strips from the outside. Screw straight through window into box sash.

Internally you will need to make up in timber arcitraves, which would be approx 100mm wide. These would need to be cut down in order to fit neatly against new window and flush with inside edge of existing box sash. If you prefer you could use pvcu architraves instead of timber.

Now glaze window and seal to finish.

Cavans Web site is at

Question submitted by Tony

I am going to fit replacement windows to a rendered house. What is the best and safest way of removing a) the glass b) the old frame. I do not wish to disturb the face rendering as it is pebble-dashed with small particles of welsh marble and would be impossible to match up.

This question answered by Cavan Sullivan of Welsh Window Systems - A very difficult question to answer without viewing site.

According to our friend Cavan Sullivan of Welsh Window Systems (A very experienced installer) he would normally suggest the following:

1. Get yourself gloves, goggles, hammer, saw, sharp, chisel, crow bar and stone chisel or bolster

2. Unscrew all opening vents and remove. With a sharp saw cut any transon or mullion sections at a slight angle (Does not include any frame attached to window perimeter) You should then be able to hit transom or mullion away from any remaining glass. 

Special Note: transom must be hit directly up or down and mullion left or right. If you hit inwards or outwards you will damage surrounding plaster and cement.

3. With a sharp chisel remove any putty holding any remaining glass in place, and remove glass. Approx 150mm up from each side cut sides at slight angle, and with a sharp chisel cut away at bottom removing in small pieces. (Try to use the chisel so the force is downwards not outwards or inwards.) Tap the remaining side directly with a hammer and then inserting a bar under the side pull directly towards the opposite side.

Finally cut top and bottom in the same manner.

Cavans Web site is at

Question submitted by Cally 

I have recently bought some white UPVC windows to replace aluminium windows to fit myself, can you give me tips on the best way to fit these windows?

This question answered by Cavan Sullivan of Welsh Window Systems.

Note: We assume that you are fitting into either face brick or rendered finish brickwork.

You can use screw and plugs, fisher bolts or tapcon type screws to fix your window to the brickwork. All screws should be plated to stop corrosion. Generally you will need 70mm 100mm and very occasionally 125mm long screws.

The exterior window sill should be fitted first if required. Make sure that if you fit an external sill you fill across both ends where the window sits with a suitable silicone. Failure to do this is a major cause of leaks where water drops down into cavity below and very often leaks over the head of any existing windows or doors below.

The window should then be offered into place. Level and plumb the window and temporary wedge into place. On large windows use a large straight edge to make sure window is level. Once you have wedged window into position stand back and check window looks correct in the opening. You will need to do this from inside and outside.

On windows less than 1200mm there is usually no need to fix the head. Windows should be fixed every 450mm and you should always keep at least 150mm away from every corner or weld. With top openers quite often there is less than 300mm between welds and in this case you should screw in the middle of whatever gap you have. If the window looks good you can proceed to completing the fit.

When fixing screws you will need to pack between the frame and the brickwork. Typically this is done with "glass packers" and you do this in order to stop the PVCu "bending" or "deflecting" as you tighten the screws. Do not over tighten screws.

One thing to watch out for - especially on wider windows is that the transoms are level. Some times if the screws are over tightened the frame may twist a little leaving the transom out of level. If the transom is our of level then the openers will not open and close correctly.

When you are happy window is fixed okay you can proceed to fit the glass. Make sure you have the correct glazing packers. Fit two bridging packers approx 150mm away from each corner. These are packers with a gap through the centre to let any water run through. Also take care not to cover drainage slots with packers. Incorrectly fitted or wrong type of packers are the cause of many premature sealed unit breakdowns. (Please note that sealed unit manufacturers will consider you have "voided" their warranty if you have placed packers in the wrong places.) Use a centre packer on panes over approx 1800mm.

If you have snap in glazing usually any frame gasket is already fitted. If not you will have to fit yourself. (NB - put the gasket join at top of window and "nip" / partially cut away at the back on the corners - in order to turn gasket at right angles - do not cut into four pieces.)

Lift glass in carefully and square up in opening with equal amounts of gasket showing on each side. You may also have to put a glazing packer on top of bridging packer if needed to lift glass to show equal gasket top and bottom. Carefully tap in beads with a rubber hammer. Its best to try a small pane first as beads are hit in differently depending on PVCU system.

Always push glass against back gasket lifting glass slightly at same time before tapping in beads or fitting an internal wedge gasket. If your windows uses wedge gasket then this gasket is pushed in last of all after fitting beads. (Fit along bottom first but with join at top - this is "important") If your window system requires you to tap in beads then fit top and bottom first followed by the sides.

On fanlights or small panes you may have to fit smallest beads first. If you have access to a low expansion gun foam you can foam around the window and when cured you can remove packers/wedges behind screws. Note - do not remove packers/wedges if fitting doors. If you do not use a foam then leave packers in but cut back flush with frame if needed.

Finally trim with PVC trims as needed and finish with a good quality low modulus silicone sealant.

Cavern's web site is found at



Site Sponsors - Please Support - Thank You

Thomas Sanderson Anglian Home Improvements

Window Quotes Here

Double Glazing

investor relations ~ disclaimer

privacy notice

attention all editors and journalists - click here

For Brochures and Quotation Requests Only
Please call us on 0845 603 6078

For contractors that would like to register with Quotatis, and for any other enquiries - Please telephone:
08448 044 344

Copyright © 1999 - 2011 Quotatis Ltd. All rights reserved.

Copyright Notice.
This web site including its source code is subject to the protection of the copyright laws of the United Kingdom and other countries. Copyright in the whole and every part of this Service belongs to Quotatis Ltd and may not be used, sold, licensed, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person other than in accordance with the terms of the Owner's agreement or otherwise without the prior written consent of the Owner. Please note: Some of the images on this site do not belong to us. We are using them with permission. You must not copy or link directly to them without permission.

Click the links below to visit some of our recommended home improvement websites

Quotatis Ltd - specialists in providing web design and marketing advice for companies supplying home improvements.

In particular we work with companies who are suppliers of conservatories, conservatory blinds, conservatory roof systems, swimming pool enclosures, double-glazing, diy plastics, casement & sash replacement windows and sunrooms.

Contact us today for help with your web design and promotion - Tel: 08448 044 344 (International: +44 1603 899910).

We work with companies in the UK, (England, Scotland, Wales, N Ireland) Eire, USA, Canada, Australia and New Zealand, offering a wide range of products such as Tilt and Turn, Casement and Sash Windows, materials such as uPVC / PVCu, Wood and Aluminium. - Providing you with information, advice and window quote requests.

Please note: All calls may be recorded or monitored for quality and training purposes.

Quotatis UK
Suite 1, Joseph King House, Abbey Farm Commercial Park, Horsham St Faith, Norwich, Norfolk, NR10 3JU
Tel: 01603 899910 - Fax: 01603 899919
Registered in England 05643725

Please Click Here To Contact Us

Replacement Windows, Conservatories, Kitchens, Bathrooms, Home Improvements