How to add trellis to the top of an old wall

[spirit]

Hello

I have a 7ft high old (victorian) wall around my garden and I want to add 2 or 3ft of trellis to the top of the wall to act as both additional security and a support for climbing plants.

I am wondering what the best way is to do this? I was originally going to simply add a wooden baton to the top of the wall and screw the bottom of the trellis panels to that but having done a bit of reading I am thing that might not be the best way for various reasons:
- may get damp into the wall
- may add stress to the wall and damage it
- does not support the sides of the trellis, so might blow down in wind (when covered with plants)

So I am now thinking that the best way might be to put posts in the ground next to the wall and screw the trellis to those so...

Can someone give please me a walkthrough of what I'll need and how to go about it? Never done anything like this before...

thanks

 

[breezer]

My 2p worth

You want to put posts in the ground that are long enough to go in the ground and stick above a 7 foot tall wall not going to look nice is it?

also if you do that you will need them at regular intervals, as standard trellis is 6 foot long, so if its only fixed at the ends thats 6 feet of trellis that can flex but if it were fixed to the wall, only 1 foot to flex (the height)

also even if you secured the posts or even the trellis to the wall you are still creating a brick wide shelf (the top of the wall with trellis on one side)

how will damp get into the wall? isnt the wall outside and does it no get rained on?

Perhaps a picture would help. how to post a picture is in forum information

 

[Thermo]

easiest way is to bolt some timber uprights 2 feet long to teh front face of the wall. 1 foot pertroudes above the wall for the trellis, the other 1 foot is below the wall and secured to it. In all honesty, what ever way you do it, it normally ends up looking a dogs dinner.

breezer is spot on about your thoughts about damp!

 

[LeadFarmer]

How about fitting some of these to the top of the wall

http://www.avsfencing.co.uk/retail/...RID=662737&DELIVERYCODE=D&IGNOREPOSTCODE=true

Not the prettiest of things but could be hidden by any climbing plants on the trellis.

 

[spirit]

Thanks for your replies

breezer - Thanks - I agree that the posts would not look good - not what I really wanted to do but I have read that fixing directly to the old wall was not advisable - so I couldn't really see what other option there was. I'm not sure I agree with you entirely about the flexing - whilst the trellis is 6ft long - it would be fixed to posts at BOTH ends - thus flexing less (I would think) than than a 2ft trellis which is fixed only on one side (the bottom. RE: the damp - yes I take your point - again just regurgitating info I had read - I have seen it mentioned in a few places that a 1" gap should be left between top of wall and trellis to allow air flow - again due to damp issues - but after more than 100yrs of british weather I guess the wall is as damp as it will ever be already...

Thermo - Thanks for your suggestion - it would work but I think that will definitely look a bit minging...

LeadFarmer - those might work but all the lateral stress is still placed on the top row of bricks when it gets windy...

Should I just go back to my original idea of fixing the trellis to a baton on top of the wall? (maybe reduce the trellis height to 1ft) - it's certainly the easiest and cheapest option.

 

[Thermo]

you wont get a great deal of wind stress with trellis. Whatever option you choose it never looks great

 

[waggonway]

It might be an idea to put small spacers under the horizontal baton (if I am getting what you mean), this would keep the majority of the wood off the top of the wall. Stopping the wood rotting on the underside and keeping the top of the wall dry.

 

[breezer]

put small spacers under the horizontal baton...................Stopping the wood rotting on the underside and keeping the top of the wall dry.

but would these spacers not act as a bridge? keeping what is above in contact with what is below

 

[mattylad]

AFAIK.

As discussion is with the trellis becoming part of the wall, I'm pretty sure that planning permission will also be needed.

As the wall is over 6'6" - requiring PP initially now, any variations to it's height will also require pp. Putting the trellis on poles in front of the wall (not affixed to it) will negate the need for pp.

So before you go ahead & do this, you may like to check with your neighbours if they would object to you adding a bit more.

Also, is the wall 100% yours on your deeds?

If any portion of it is a shared/party wall then you need permission from the other half owner/neighbour before adding anything to the wall.

GardenLaw is a good site for clarification of this sort of information.

 

[tigsmom]

I don't want to seem like I'm butting in but I have done this in my garden. I put treated timber batons on the centre of the top of the wall using those nail/screw things that have plugs already attached. You drill a hole through the baton & into the wall, then hammer them in, then screw them up. Then we fixed the trellis (2' high) to the side of this baton using exterior screws. It was pretty sturdy & we struggled to get them off even when we demolished the wall 4 years later. We didn't have plants on them though we just painted them.