GRP v solid wood external

[graemezz]

I am looking at replacing an old upvc front door with something else.
GRP I see is a sub-version of composite and cheaper. How easy is it to fit locks to it rather than solid wood?
Which is stronger grp or 44mm wood?
Someone said fixing multi point lock to grp is fiddly.

 

[crank39]

If the difference between GRP and composite door is the GRP is a foam core whilst the composite is a solid timber core then i'd prefer a composite just for strength, however I'm confused about why you want to fit multi point locks to them when 99% already come with them already fitted, just curious

 

[graemezz]

The ones i saw seem to be plain like https://deal4doors.co.uk/products/grp-colonial-6p-white. Maybe if you spend more it comes with pre-fittings.
Thank you

 

[crank39]

That's an internal door surely?

 

[graemezz]

Defo external but seems to be a door with nothing on it

 

[HomeESSWindows]

Full disclosure first: I'm with Home Energy Saving Solutions (Home ESS), a family-run window and door firm in Manchester, and we fit composite doors, so bear that in mind. I'm not trying to sell you anything here, just something that might save you a headache.

I think the reason the door you found looks so plain is that it's a door slab (just the leaf), not a doorset. Most composite and GRP-skinned front doors are sold as a complete doorset: the leaf comes already hung in its own frame, with the multi-point lock, hinges, threshold and glass fitted at the factory. That's why crank39 says 99% come with the lock already on. You take out the old uPVC door and frame and fit the whole set as one unit.

If you buy a bare slab you take all of that on yourself:

- routing a long, accurate mortice down the edge for a multi-point lock and lining the keeps up with the frame. This is the fiddly bit people warn you about, and if it's slightly out the door won't lock smoothly or seal properly
- hanging it, plus a letterbox, cylinder and any glazing
- a frame to hang it in. An old uPVC door frame is made for its own uPVC door, so it almost certainly won't take a 44mm slab. You'd be replacing the frame anyway.

On strength, a good composite doorset and a good 44mm hardwood door are both solid. In practice, how secure a front door is comes down more to the lock, the cylinder (get an anti-snap one) and how well the door is fitted and fixed than to GRP versus timber. GRP-skinned doors don't need painting and won't swell or warp the way timber can, which is why most people replacing a uPVC front door end up going composite.

So for a DIY job I'd look for a supplier who sells the door as a complete, pre-hung doorset made to your opening size, rather than a slab. Measure the brick opening, not the old frame, and check whether the price includes the lock, cylinder and threshold. For reference, our own fitted composite doors start from £1,000 and the final price depends on the style, colour and extras, so that gives you something to compare a supply-only price against.

Hope that helps, and good luck with it.

 

[graemezz]

Thank you.
The last place I swapped to a solid wood door it came to around £1k inc labour and parts.
That door was not exposed directly to the elements though.
I would not try it myself.