Can I lay Amtico directly onto 18mm ply or do I need to prep the ply ?

I have replaced some MDF door thresholds with 18mm plywood to the EN 314-2 Class 3 standard as specified by Amtico.

Can I glue the Amtico directly to the plywood or do I need to prepare the plywood before laying the Amtico e.g. prime or screed ?

I have Amtico SF Adhesive, Amtico International Adhesive Remover and an 18cm Spreader Handle - I used this a year ago to refit existing Amtico that had come away due to being poorly fitted by the contractor.

Pictures are below for reference...

ORIGINAL MDF DOOR THRESHOLDS

FRONT DOOR:

PATIO DOOR:


REMOVED MDF DOOR THRESHOLDS

FRONT DOOR:


PATIO DOOR:





FLOORING CLEANED:

FRONT DOOR



PATIO DOORS



PLY FITTED:

FRONT DOOR



PATIO DOORS



The original MDF door thresholds were just glued to the floor using expanding foam, so I used the same method to fit the ply wood.

I did add some screws in the concrete floor to hold the ply wood whilst the foam set - I'm not sure whether to leave these screws in (after counter sinking them into the ply) or remove them. If I were to leave the screws in, what type of filler should I use to fill over the screws ?

As shown in the picture below, the floor is made up of:

1. Concrete floor
2. Polystyrene (black)
3. Concrete bricks
4. Air gap



I am reluctant to fill the air gap because I presume its there for a reason, such as ventilation or damp prevention ?

There is a noticeable draft coming from the air gap, if I were to fill it (e.g. with concrete) then could this cause issues with dampness etc ?

The concrete bricks are not level with each other, nor the concrete floor. I presume this is why the builders used expanding foam to fit the original MDF thresholds ?

I realise that the construction of the floor underneath the thresholds is not ideal and I am not sure what (if anything) can be done to resolve that ?

I am trying to make the best of what I have, either way it can't be worse than the original painted MDF door thresholds which were far from hard wearing and looked terrible.

 

You could probably put some insulation in the gap, fill the screw holes with any hard set filler and stick the Amtico direct to that ply


Sent from my iPhone using Tapatalk

 

You should put a vertical dpm against the outer wall , then as said some insulation.
Keep the screws in , not all expanding foams are the same . Some are adhesives, some only expand slightly and some just keep on growing !

Ta

 

Thanks for the replies.

I used Soudal Adhesive Foam Hand-Held 750ml (from Screwfix) to glue the ply wood to the floor.

Unfortunately as you might tell from the pictures I glued the plywood to the floor a week ago so its probably not possible to remove the ply wood without damaging it. I have now counter sank and filled the screws so I can glue the Amtico this weekend.

Is it too late to put vertical dpm against the outer wall ? I don't know what this is other than googling and finding out its damp proof membrane.

If this is needed then Im surprised it wasn't fitted originally - the house is only 4 years old.

Out of interest, what sort of insulation would be fitted, something like fibre glass loft insulation ?

And again, if this is needed then how come it wasn't fitted when the original mdf door thresholds were fitted ?

I basically copied the existing structure, but I replaced the mdf with ply wood as this was recommended for fitting the Amtico to.

 

Standard new house build procedure, cover up a huge void with MDF

 

your question :

And again, if this is needed then how come it wasn't fitted when the original mdf door thresholds were fitted ?

This is because most new builds are now a joke and are pushed to get the building thrown up as quick and as cheaply as they can get away with plus the Brucie added bonus of cutting as many corners as possible........Good game Good game.

A new build estate near us nearly all the gardens front and back are finishing 1 brick course higher than the DPC the drives slope down to garages with no surface drainage ACOs so they will floor under the garage door, silicon on every edge corner and people are paying excess of £650000. Pay your money take your chance

 

"This is because most new builds are now a joke and are pushed to get the building thrown up as quick and as cheaply as they can get away with"

This is something I've long suspected... which is why I found it such a difficult pill to swallow when I got on the housing ladder. Most houses, both new and old, are well over priced and like you said new builds are put up as quickly and cheaply as possible yet the prices are over inflated. I had to use help to buy to get on the housing ladder and for some stupid reason that scheme only applies to new builds.

I do all my own DIY and when I ask for advice (like on this forum) people have pointed out other poor build practices which makes me angry, thinking it should have been done right in the first place and if not it should be rectified or compensated for.

The example of this particular DIY job is an example - why on earth would you fit painted MDF for a door threshold !?? Its obvious that a painted piece of MDF is a bad choice for a door threshold and will quickly wear out, which is why I have decided to replace it with Amtico. They fitted Amtico in the hallway and kitchen so why didn't they use Amtico at the door thresholds.

The next DIY job I'm thinking of is to add another radiator in the living room as currently there is only one radiator which is too small for the room.

On top of these types of issues I also had the usual snagging list which is expected but the customer service was terrible (Crest Nicholson) - they were keen when it came to selling the house but they didn't want to know once they had my money.

 

^^^ this was one of many rads I've came across on newbuilds.....I just dont get it

 

If you have given your house builder a chance to rectify your defects, and they are not to your satisfaction, you should contact the NHBC.
They will look into this for you, and if upheld they will nominate a separate company to come in, and complete remedial works.
Your house builder won`t like it, but thats how it works.
A friend of mine set up a company which completes this type of work and now has around 20 guys out on site every day, just doing this work.

 

Its a joke isn't it ! I don't know whether its because they are building in a rush to unrealistic deadlines or just can't be bothered or a combination of the both ? Surely no one can be that incompetent as to not fit a radiator level !

 

Fortunately most of the snagging items were not serious and have been rectified, but it took a lot of grief to get them to rectify them. I had to chase them constantly and complain again and again. Snagging items were only covered in the first year so theres nothing I can do about further issues now. The boiler failed a week after the 2 year warranty - being a hands-on engineer I was able to fix it myself.

But its the comments I hear about how the build quality is poor (such as mentioned in this post) and it makes me wonder what else could be wrong. I don't know much at all about building houses and even if I did there are parts not visible.

 

In another post somewhere else (not on this forum and I remember where I posted) someone criticised this drawing I managed to get hold of for the wall construction. I cant remember what they said but it was something along the lines of what was mentioned earlier in this post, about how badly built new houses are.

 

Its took a customer of mine 19 months and a tribunal to get his sink put in the 'correct' place in his new build.

Where it should have been is common sense but where they put it made no sense yet the housebuilders said he will have to live with it and that's even the customer waving a copy of his plans at them which shown that the sink was in the wrong place.

I would never buy a new build, only way I'd live in one is if I built it myself

 

Last time I was on a new build site I asked the foreman what levelling compound they had used as it was terrible. His reply was the cheapest one lol. All needed to be removed before the hardflooring could be installed. I would say 80% of new builds are built with subfloors that are not suitable for hardflooring and are no way near the so called British standards.


Sent from my iPhone using Tapatalk

 

As Dan says but I’d say 95%

 

80% you’re lucky, since 1988 we’ve seen 3 yes 3 floors done to a relatively decent standard where we’ve not had to do tons of remedial work.


Sent from my iPhone using Tapatalk

 

You guys are right. I do have a few builders I work with that now get the floors screeded to perfection so I’m lucky but yeah new build is probably 95%


Sent from my iPhone using Tapatalk

 

Im not 100% but I think its 5 years with NHBC.
New build is shite, no doubt about that. We have worked in them on and off for years, and some are better than others.
I have found Kier, at least the sites we have been on, to have the best standard. They will not accept any poor workmanship.
There are some that do have standards, other just dont care